public class SendSMS{

    Public string SMS{get;set;}
    Public string useThisTemplate{get;set;}
    Public List<Contact> conList {get;set;}
    Public List<Lead> leaList {get;set;}
    Public List<Deelnemer_Evenement_Training__c> DeeList {get;set;}
    Public void setCheckboxValue()
    {
    }

    Public List<string> idList = new List<string>();
    Public List<SMS_Templates__c> templates = new List<SMS_Templates__c>([SELECT Name, SMS_Text__c FROM SMS_Templates__c WHERE Inactive__c = FALSE]);
    Public Map<string, string> templateMap = new Map<string, string>();

    Public List<string> telList = new List<string>();

    public PageReference iniciaMisto(){
    
        //busca defaults ORG / USER:
        SMSMessageBirdKey__c mbkey = SMSMessageBirdKey__c.getInstance();
        string defaultCCorg = mbkey.Default_Country_Code__c;
        
        string userId = UserInfo.getUserId();
        User u = [SELECT Default_Country_Code_for_SMS__c FROM User WHERE id =: userId];
    
        //constroi a lista dos ids
        string idsString = ApexPages.currentPage().getParameters().get('recordIds');
        if(idsString != null){
            idList = idsString.split(',');

        
            //constroi a lista de Contactos / Leads:
            try{
                conList = [SELECT id, Name, MobilePhone, Alert_SMS_sent__c FROM Contact WHERE id IN: idList LIMIT 4000];
                
                for(Contact c: conList){
                    if(c.MobilePhone != null && c.MobilePhone != ''){
                        string numAux = c.MobilePhone.trim();

                        system.debug('\n\n### --- numAux: '+numAux);
                       
                       //ADD COUNTRY CODE (IF NEEDED):
                       IF( numAux.indexOf('+') == -1 ){
                       
                           //limpa caracteres especiais e leading zeros:
                            try{ numAux = numAux.trim().replaceAll('[^0-9]',''); }catch(exception ex2){}
                            integer numInt = integer.valueOf(numAux);
                            numAux = string.valueOf(numInt); 
                       
                           if(u.Default_Country_Code_for_SMS__c != '' && u.Default_Country_Code_for_SMS__c != null){
                               numAux = u.Default_Country_Code_for_SMS__c + numAux;
                           }else{
                               numAux = defaultCCorg + numAux;
                           }
                       }
                        
                        try{ numAux = numAux.replaceAll('[^0-9]',''); }catch(exception ex3){}
                        
                        system.debug('\n\n### --- numAux final: '+numAux);
                        
                        telList.add(numAux);
                    }
                }
                
                
                
            }catch(exception ex){}
            
            if(conList.size() > 0){
                string numbC = string.valueOf(conList.size());
                ApexPages.Message msg = new ApexPages.Message(ApexPages.severity.info, numbC + ' Contacts selected (max: 4000)');
                ApexPages.addMessage(msg);
            }
            
                try{
                    leaList = [SELECT id, Name, MobilePhone FROM Lead WHERE id IN: idList LIMIT 4000];
                
                    for(Lead c: leaList){
                        if(c.MobilePhone != null && c.MobilePhone != ''){
                            string numAux = c.MobilePhone.trim();
                            
                           system.debug('\n\n### --- numAux: '+numAux);
                       
                           //ADD COUNTRY CODE (IF NEEDED):
                           IF( numAux.indexOf('+') == -1 ){
                           
                               //limpa caracteres especiais e leading zeros:
                                try{ numAux = numAux.trim().replaceAll('[^0-9]',''); }catch(exception ex2){}
                                integer numInt = integer.valueOf(numAux);
                                numAux = string.valueOf(numInt); 
                           
                               if(u.Default_Country_Code_for_SMS__c != '' && u.Default_Country_Code_for_SMS__c != null){
                                   numAux = u.Default_Country_Code_for_SMS__c + numAux;
                               }else{
                                   numAux = defaultCCorg + numAux;
                               }
                           }
                            
                            try{ numAux = numAux.replaceAll('[^0-9]',''); }catch(exception ex3){}
                            
                            system.debug('\n\n### --- numAux final: '+numAux);
                            
                            telList.add(numAux);
                        }
                    }
                
                    
                }catch(exception ex2){}
                
                try{
                    DeeList = [SELECT id, Name, Mobile_phone__c, Deelnemer__c FROM Deelnemer_Evenement_Training__c WHERE id IN: idList LIMIT 4000];
                
                    for(Deelnemer_Evenement_Training__c c: DeeList){
                        if(c.Mobile_phone__c != null && c.Mobile_phone__c != ''){
                            string numAux = c.Mobile_phone__c.trim();
                            
                           system.debug('\n\n### --- numAux: '+numAux);
                       
                           //ADD COUNTRY CODE (IF NEEDED):
                           IF( numAux.indexOf('+') == -1 ){
                           
                               //limpa caracteres especiais e leading zeros:
                                try{ numAux = numAux.trim().replaceAll('[^0-9]',''); }catch(exception ex2){}
                                integer numInt = integer.valueOf(numAux);
                                numAux = string.valueOf(numInt); 
                           
                               if(u.Default_Country_Code_for_SMS__c != '' && u.Default_Country_Code_for_SMS__c != null){
                                   numAux = u.Default_Country_Code_for_SMS__c + numAux;
                               }else{
                                   numAux = defaultCCorg + numAux;
                               }
                           }
                            
                            try{ numAux = numAux.replaceAll('[^0-9]',''); }catch(exception ex3){}
                            
                            system.debug('\n\n### --- numAux final: '+numAux);
                            
                            telList.add(numAux);
                        }
                    }
                
                    
                }catch(exception ex2){}
                
                if(leaList.size() > 0){
                    string numbL = string.valueOf(leaList.size());
                    ApexPages.Message msg = new ApexPages.Message(ApexPages.severity.info, numbL + ' Leads selected (max: 4000)');
                    ApexPages.addMessage(msg);
                }
                                
                if(leaList.size() == 0 && conList.size() == 0 && DeeList.size() == 0){
                    ApexPages.Message msg = new ApexPages.Message(ApexPages.severity.error, 'No Contacts or Leads selected...');
                    ApexPages.addMessage(msg);
                }

        
        }else{
            ApexPages.Message msg = new ApexPages.Message(ApexPages.severity.error, 'No Contacts or Leads selected...');
            ApexPages.addMessage(msg);
        }
    
    return null;
    }

    public PageReference caVaiDisto(){

        system.debug('\n\n### --- SMS TO SEND: '+SMS);
        system.debug('\n\n### --- NUMBERS TO SEND: '+telList);
        
        id userId = UserInfo.getUserId();
        
        if(SMS == null || SMS == '' || telList.size() == 0){
            if(telList.size() == 0){
                ApexPages.Message msg = new ApexPages.Message(ApexPages.severity.error, 'You must have at least one Contact to send the SMS...');
                ApexPages.addMessage(msg);
            }else{
                ApexPages.Message msg = new ApexPages.Message(ApexPages.severity.error, 'You must specify the SMS text...');
                ApexPages.addMessage(msg);
            }
        }else{
        
            //ENVIA A CENA:
            string resultadoDaCena = SendSMSMessageBird.enviaMisto(telList, SMS);
            
            //...E GRAVA TASKS:
            List<Task> tList = new List<Task>();
            if(conList != null && conList.size() > 0){
                for(Contact c: conList){
                    Task tWa = new Task();
                    tWa.WhoId = c.Id;
                    tWa.OwnerId = userId;
                    tWa.Status='Completed';
                    string subject = '';
                    subject = 'SMS sent: '+SMS;
                    tWa.Subject = subject.abbreviate(254);
                    tWa.Description = 'SMS sent to number: '+c.MobilePhone+'\n'+'SMS text: '+SMS;
                    tWa.Type = 'SMS';
                    tList.add(tWa);
                }
            }
            
            if(DeeList != null && DeeList.size() > 0){
                for(Deelnemer_Evenement_Training__c c: DeeList){
                    Task tWa = new Task();
                    tWa.Whatid = c.Id;
                    tWa.Whoid= c.Deelnemer__c;
                    tWa.OwnerId = userId;
                    tWa.Status='Completed';
                    string subject = '';
                    subject = 'SMS sent: '+SMS;
                    tWa.Subject = subject.abbreviate(254);
                    tWa.Description = 'SMS sent to number: '+c.Mobile_phone__c+'\n'+'SMS text: '+SMS;
                    tWa.Type = 'SMS';
                    tList.add(tWa);
                }
            }
            
            if(leaList != null && leaList.size() > 0){
                for(Lead c: leaList){
                    Task tWa = new Task();
                    tWa.WhoId = c.Id;
                    tWa.OwnerId = userId;
                    tWa.Status='Completed';
                    string subject = '';
                    subject = 'SMS sent: '+SMS;
                    tWa.Subject = subject.abbreviate(254);
                    tWa.Description = 'SMS sent to number: '+c.MobilePhone+'\n'+'SMS text: '+SMS;
                    tWa.Type = 'SMS';
                    tList.add(tWa);
                }
            }
            
            if(tList.size() > 0){
                insert tList;
            }
        
            //...E INFORMA QUE TUDO CORREU BEM...
            ApexPages.Message msg = new ApexPages.Message(ApexPages.severity.info, tList.size() + ' SMS sent');
            ApexPages.addMessage(msg);
            
            //...E MOSTRA O RETURN MESSAGE (NOT!):
            /**
            ApexPages.Message msg2 = new ApexPages.Message(ApexPages.severity.info, resultadoDaCena);
            ApexPages.addMessage(msg2);
            */
        }
        
        
    return null;
    }


    public void changeTemplateText(){
        system.debug('\n\n### --- templateMap: '+templateMap);
        system.debug('\n\n### --- useThisTemplate: '+useThisTemplate);
        SMS = templateMap.get(useThisTemplate);
        system.debug('\n\n### --- SMS CHANGE TEMPLATE TEXT: '+SMS);
    
    }
    

    public List<SelectOption> getTemplateSelectOptions() {
    
        List<SelectOption> options = new List<SelectOption>();  
        options.add(new SelectOption('','--none--'));
        for(SMS_Templates__c t: templates){
            options.add(new SelectOption(t.Name,t.Name));
            //aproveita para construír o mapa:
            templateMap.put(t.Name, t.SMS_Text__c);
        }
        return options;
        
    }

}

<apex:page tabStyle="Contact" controller="SendSMS" action="{!iniciaMisto}">
  <apex:form >
  
    <apex:sectionHeader title="Mass" subtitle="Send SMS" />
    <apex:pageMessages escape="false"/>
    <br/>
  
    <apex:pageBlock >
    <apex:pageBlockSection title="Contact List" columns="1" collapsible="false">
        <apex:pageBlockTable value="{!conList}" var="item">
            <apex:column value="{!item.Alert_SMS_sent__c}"/>
            <apex:column value="{!item.Name}"/>
            <apex:column value="{!item.MobilePhone}"/>
            <apex:actionFunction action="{!setCheckboxValue}"immediate="true"oncomplete="setCheckboxValue();" rerender="{!item.Alert_SMS_sent__c}"/>
           

define once function in javascript

<script>

function setCheckboxValue()
{
      document.getElementById('item.Alert_SMS_sent__c').Selected = true;

}
</script>

        </apex:pageBlockTable>
        <apex:pageBlockTable value="{!leaList}" var="item">
            <apex:column value="{!item.Name}"/>
            <apex:column value="{!item.MobilePhone}"/>
        </apex:pageBlockTable>
        <apex:pageBlockTable value="{!DeeList}" var="item">
            <apex:column value="{!item.Name}"/>
            <apex:column value="{!item.Mobile_phone__c}"/>
        </apex:pageBlockTable>
    </apex:pageBlockSection>
    
    
    <apex:pageBlockSection title="Select SMS Template" columns="1" collapsible="false">
        <apex:selectList value="{!useThisTemplate}" size="1" title="Choose a template" >
            <apex:actionSupport event="onchange" rerender="textSection" action="{!changeTemplateText}" />
            <apex:selectOptions value="{!TemplateSelectOptions}"/>
        </apex:selectList>
        
        <apex:pageBlockSection id="textSection" columns="1" collapsible="false" title="SMS Text">   
            <apex:inputTextArea id="SMSText" style="width:400px;height:80px;" value="{!SMS}"/>
        </apex:pageBlockSection>
    </apex:pageBlockSection>
    
    
    
    <apex:pageBlockButtons >
            <apex:commandButton action="{!caVaiDisto}" value="Send" />
            &nbsp; <apex:outputLink value="/home/home.jsp" id="cancelLink">Cancel</apex:outputLink>
    </apex:pageBlockButtons>
        
    
    
    </apex:pageBlock>

  </apex:form>
</apex:page>