I've an issue while sorting date by arrow sorting. I successfully implemented this for "Subject" and "Status" field on Task object but while i click on Date column , it gives me error saying : unexpected token: <EOF> Error is in expression '{!toggleSort}' in page new_test_task_assignment: Class.PagingTasksController1.toggleSort: line 61, column 1

I've given endless try but still the same . Can anyone please help me to correct my mistake(s) .. Please help .

Thanks in advance.
 Marc   

public class PagingTasksController1{
    
    public List<Task> tasks {get;set;}
    public Task del;
    public Task taskDel;
    public Integer CountTotalRecords{get;set;}
    public String QueryString {get;set;}
    public Integer OffsetSize = 0;
    private Integer QueryLimit =3 ;
    public List<Task> lstTasks {get;set;}
    public String searchText {get;set;}
    public String rowIndex {get;set;}
    public Date mydate;
    public Integer totalCount {get;set;}
    public string sortField = 'Subject';  // default sort column
    private string sApplySOQL = '';
    public List<Task> delattendeeList {get;set;}
    
    public List<Task> delAttendees {get; set;}
    
    public PagingTasksController1(ApexPages.StandardController controller) {
        
        taskDel= (Task)controller.getRecord();
        tasks = [Select id,Subject,Status,ActivityDate,Owner.Name from Task];
        // this.Tasks=Tasks[0];
        totalCount = Tasks.size();
        
        delattendeeList = new List<Task>();
        delattendees = new List<Task>();
    }
    
    
    // the current sort direction. defaults to ascending
    public String sortDir {
        get  { if (sortDir == null) {  sortDir = 'asc'; } return sortDir;  }
        set;
    }
    
    // the current field to sort by. defaults to role name
    public String getsortField() {
        return sortField;
    }
    
    // the current field to sort by.
    public void setsortField(string value) {
        sortField = value;
    }
    
    // toggles the sorting of query from asc<-->desc
    public void toggleSort() {
        // simply toggle the direction
        sortDir = sortDir.equals('asc') ? 'desc' : 'asc';
        
        integer iIndex = sApplySOQL.indexOf('Order By');
        if (iIndex > -1){
            sApplySOQL = sApplySOQL.substringBefore('Order By');
            sApplySOQL = sApplySOQL + ' Order By ' + sortField + ' ' + sortDir +  ' limit ' + QueryLimit + ' offset ' + OffsetSize;
        }
        
         System.debug('Before Sorted Date is ' +sApplySOQL);
         tasks = Database.query(sApplySOQL );  // here it where gives me error
         
    }
       
    public PagingTasksController1 (){
        //CountTotalRecords= [select count() from Task];
        //String qStr2= '7/23/2014';
        
    }
    
    /* public List<Task> getTasks(){
    if(tasks == null){
    tasks = new List<Task>();
    }
    return tasks;
    }  */
    
    public void findTasks(){
        String qStr2 = 'Select count() from Task where Subject like \'%'+searchText+'%\' OR Status like \'%'+searchText+'%\'';
        CountTotalRecords = Database.countQuery(qStr2);
        queryTasks();
    }
    
    public void queryTasks(){
        
        String qStr2= searchText;
        String strnormal = '';
        try{
            mydate = date.parse(qStr2);
        }catch(Exception e)
        { }
        
        String strDate = '';
        if(mydate != null) {
            // strnormal = String.valueOf(mydate );
            String[] qstr3 = String.valueOf(mydate).split(' ',2);
            strDate = ' ActivityDate =  '+ qstr3[0] + ' ';
        }else{
            
            strDate  =  '(Subject like \'%'+searchText +'%\' OR Status like \'%' +searchText+ '%\' OR Owner.Name like \'%' +searchText+ '%\') ' + ' Order By '  + sortField;
        }
        
        String qStr = 'Select Owner.Name,Subject,Status,ActivityDate from Task where '+strDate+' limit ' + QueryLimit + ' offset ' + OffsetSize;
        System.debug(qStr);
        tasks = Database.query(qStr);
        
    }
    
    public Boolean getDisablePrevious(){
        if(OffsetSize>0){
            return false;
        }
        else return true;
        }
    
    public Boolean getDisableNext() {
        if (OffsetSize + QueryLimit < countTotalRecords){
            return false;
        }
        else return true;
        }
    
    public PageReference Next() {
        OffsetSize += QueryLimit;
        queryTasks();
        return null;
    }
    
    public PageReference Previous() {
        OffsetSize -= QueryLimit;
        queryTasks();
        return null;
    }
    
    public PageReference save() {
        update tasks;
        return ApexPages.CurrentPage();
    }
    
    public void deleteRow(){
        delete new Task(Id = rowIndex);
        for (Integer i = 0; i < Tasks.size(); i++) {
            if (Tasks[i].Id == rowIndex) {
                Tasks.remove(i);
                break;
            }
        }
    }
}

====== Page =====

<apex:page controller="PagingTasksController1" docType="html-5.0">
    <apex:form >
     <apex:variable var="rowNumber" value="{!0}"/>
        <apex:pageBlock title="Tasks" id="pgBlock" >
            <apex:pageBlockButtons >
               <apex:commandButton action="{!save}" id="saveButton" value="Save"/>
               <apex:commandButton onclick="resetInlineEdit()" id="cancelButton" value="Cancel"/>
            </apex:pageBlockButtons>
        <apex:inlineEditSupport showOnEdit="saveButton, cancelButton"
                    hideOnEdit="editButton" event="ondblclick"
                    changedStyleClass="myBoldClass" resetFunction="resetInlineEdit"/> 
        <apex:inputText id="searchBox" value="{!searchText}"/>
        <apex:commandButton value="Search" reRender="pgTable,pgBlock" action="{!findTasks}"/>
        
        <apex:pageBlockTable value="{!Tasks}" var="tsk" id="pgTable">
           <apex:column headerValue="Action" >
              <apex:commandButton value="Delete" action="{!deleteRow}" reRender="pgTable"> 
                 <apex:param name="rowIndex" value="{!tsk.id}" assignTo="{!rowIndex}" />
              </apex:commandButton>              
           </apex:column> 
           
        <!-- <apex:column headerValue="Action" >
          <apex:outputLink value="{!URLFOR($Action.Task.Delete, .id,['retURL'='/apex/New_Test_task_Assignment'])}"> Delete</apex:outputLink>
        </apex:column>  -->
        <apex:column headerValue="Subject">
            <apex:facet name="header">
                <apex:commandLink value="Subject" action="{!toggleSort}" rerender="pgTable" >
                  <apex:param name="sortField" value="Subject" assignTo="{!sortField}"/>
                    <apex:outputPanel rendered="{!BEGINS(sortField,'Subject')}">
                        &nbsp;<apex:image value="{!IF(sortDir = 'desc','/img/arrowDown.gif','/img/arrowUp.gif')}"/>
                    </apex:outputPanel>
                </apex:commandLink>
            </apex:facet>     
          <apex:outputField value="{!tsk.Subject}"/>
        </apex:column>
           
        <apex:column headerValue="Status">
            <apex:facet name="header">
                <apex:commandLink value="Status" action="{!toggleSort}" rerender="pgTable" >
                      <apex:param name="sortField" value="Status" assignTo="{!sortField}"/>
                        <apex:outputPanel rendered="{!BEGINS(sortField,'Status')}">
                          &nbsp;<apex:image value="{!IF(sortDir = 'desc','/img/arrowDown.gif','/img/arrowUp.gif')}"/>
                        </apex:outputPanel>
                </apex:commandLink>
            </apex:facet>         
            <apex:outputField value="{!tsk.Status}"/>
        </apex:column>
       
        <apex:column headerValue="Assigned To">
            <apex:outputField value="{!tsk.Owner.Name}"/>
        </apex:column>
        
       <apex:column headerValue="Due Date">
          <apex:facet name="header">
                <apex:commandLink value="ActivityDate" action="{!toggleSort}" rerender="pgTable" >
                      <apex:param name="sortField" value="ActivityDate" assignTo="{!sortField}"/>
                        <apex:outputPanel rendered="{!BEGINS(sortField,'ActivityDate')}">
                          &nbsp;<apex:image value="{!IF(sortDir = 'desc','/img/arrowDown.gif','/img/arrowUp.gif')}"/>
                        </apex:outputPanel>
                </apex:commandLink>
          </apex:facet>     
          <apex:outputField value="{!tsk.ActivityDate}"/>
        </apex:column>   
   </apex:pageBlockTable>
     <apex:pageBlockButtons >
         <apex:commandButton value="Previous" action="{!Previous}" rerender="pgTable,pgBlock"
                                    status="status" disabled="{!DisablePrevious}" />
          <apex:commandButton value="Next" action="{!Next}" reRender="pgTable,pgBlock"
                                  status="status" disabled="{!DisableNext}" />
            <apex:actionStatus id="status" startText="Please Wait..."/>
         </apex:pageBlockButtons>
      </apex:pageBlock>
    </apex:form>
  </apex:page>