I have written two separate visual force pages to prepopulate and add rows dynamically. I would like to know how to merge these two codes. Can some help me with this coding please.
 

PREPOPULATE
<apex:page standardController="IT_Contract_Line__c" extensions="Autocall,AddNewRows" showHeader="true" sidebar="true">
<apex:form >
<apex:pageBlock >
    
 <apex:pageBlockSection >
 <apex:pageBlockTable value="{!cwrap}" var="cn">
       <apex:column headerValue="Product">
<apex:inputField value="{!Testing.Product__c}" >
    <apex:actionSupport event="onchange"  action="{!autoCal}"   reRender="accEmail,accPhone">
</apex:actionSupport>
</apex:inputField>
</apex:column>
<apex:column headerValue="UOM">
<apex:inputField value="{!Testing.UOM_Unit_Of_Measure1__c}"  id="accEmail"  html-disabled="true"/>
</apex:column>
<apex:column headerValue="Unit Price">
<apex:inputField value="{!Testing.Unit_Price__c}"  id="accPhone"/>
</apex:column>
<apex:column headerValue="QUantity">
<apex:inputField value="{!Testing.Quantity__c}"/>
</apex:column>
<apex:column headerValue="Discount">
<apex:inputField value="{!Testing.Unit_Discount__c}"/>
</apex:column>
<apex:column headerValue="Line Tax">
<apex:inputField value="{!Testing.Line_Tax__c}"/>
</apex:column>
<apex:column headerValue="IT-Contracts">
<apex:outputField value="{!Testing.IT_Contracts__c }"  html-disabled="true"/>
</apex:column>
</apex:pageBlockTable>
</apex:pageBlockSection>
<apex:commandButton value="AddRow" action="{!addRows}" reRender="lab"/>
<apex:commandButton value="Save" action="{!save}" />
</apex:pageBlock>
</apex:form>
</apex:page>
PREPOPULATE
public class Autocall {
public IT_Contract_Line__c Testing {get;set;}
public boolean flag{get;set;}
private ApexPages.StandardController stdController;
public Autocall(ApexPages.StandardController controller) {
Testing=(IT_Contract_Line__c)controller.getRecord();
}
//function is called from actionsupport event

public PageReference autoCal()
{
Id accId = Testing.Name;     // collecting account id from visualforce page
List<Product2> accLst = [select id,UOM__c,List_Price__c from Product2 where id=:Testing.Product__c];
Testing.UOM_Unit_Of_Measure1__c = accLst[0].UOM__c; 
Testing.Unit_Price__c = accLst[0].List_Price__c;
return null;
}
 public PageReference save()
{
upsert Testing;
flag=true;
    PageReference nextPage = new ApexPages.StandardController(Testing).view();
        nextPage.setRedirect(true);      
        return nextPage;

}
}

ADD ROWS DYNAMICALLY
<apex:page standardController="IT_Contract_Line__c"  recordSetVar="IT_Contract_Line__c" extensions="ITContractLines">
     <apex:form > 
        <apex:pageBlock >
             <apex:pageBlockSection title="Add Vendor QuoteLines" columns="1">
             <apex:pageBlockTable value="{!listMeetingAttendee}" var="meetAtt" id="customTable">
             <apex:column headerValue="Product">
                 <apex:inputField value="{!meetAtt.Product__c}" required="true"/>
             </apex:column>
                 <apex:column headerValue="Quantity">
                 <apex:inputField value="{!meetAtt.Quantity__c}"/>
             </apex:column>
             <apex:column headerValue="Unit Price">
                 <apex:inputField value="{!meetAtt.Unit_Price__c }"/>
             </apex:column>             
                 <apex:column headerValue="Unit Discount">
                 <apex:inputField value="{!meetAtt.Unit_Discount__c}"/>
             </apex:column>
                  <apex:column headerValue="Line Tax">
                 <apex:inputField value="{!meetAtt.Line_Tax__c}"/>
             </apex:column>
             <apex:column headerValue="IT-Contract">
                 <apex:outputField value="{!meetAtt.IT_Contracts__c }"  html-disabled="true"/>
             </apex:column>
                 <apex:column id="two">
               <apex:commandButton value="Remove LineItem" action="{!removerow}"/>  
              </apex:column>
             </apex:pageBlockTable>
             </apex:pageBlockSection>
             <apex:pageBlockButtons >
                 <apex:commandButton value="Add IT-ContractLines" action="{!addLineItem}" rerender="customTable" immediate="true"/>
                 <apex:commandButton value="Save IT-ContractLines" action="{!saveLineItem}"/>
                 <apex:commandButton value="Cancel" action="{!cancel}" immediate="true"/>
             </apex:pageBlockButtons>
             
         </apex:pageBlock> 
     </apex:form>
</apex:page>
ADD ROWS DYNAMICALLY
public class ITContractLines {
public List<IT_Contract_Line__c> listMeetingAttendee {get; set;}
    IT_Contract_Line__c meetingAttendee = new IT_Contract_Line__c();
   IT_Contracts__c meetingAttendees = new IT_Contracts__c();
    public String KARId = apexpages.currentpage().getParameters().get('Id');
     public ApexPages.StandardSetController stdCntrlr {get; set;}
     public ITContractLines(ApexPages.StandardSetController controller) { 
     stdCntrlr = controller;
        listMeetingAttendee = new List<IT_Contract_Line__c>();
        system.debug(KARId);
        if(KARId<>null){
            for(IT_Contracts__c KAR: [SELECT Id FROM IT_Contracts__c WHERE Id =:KARId ]){
                meetingAttendee.IT_Contracts__c = KARId ;
                listMeetingAttendee.add(meetingAttendee );
            }      
        } else{
             listMeetingAttendee.add(meetingAttendee );
        }
        
    }
    public void addLineItem(){
        IT_Contract_Line__c meetAtt = new IT_Contract_Line__c();
        meetAtt.IT_Contracts__c = KARId ;
        listMeetingAttendee.add(meetAtt);
    }
    public PageReference saveLineItem() {
         system.debug('listMeetingAttendee'+listMeetingAttendee);
        for(Integer i=0; i<listMeetingAttendee.size(); i++)
        {
            upsert listMeetingAttendee;
        }
        PageReference nextPage = new ApexPages.StandardController(meetingAttendees).view();
        nextPage.setRedirect(true);      
        return nextPage;
        }
    public void removerow()
     { 
         Integer i = listMeetingAttendee.size();
          listMeetingAttendee.remove(i-1);
     }
         public PageReference cancel(){
         Id ide =  ApexPages.Currentpage().getParameters().get('id'); 
         return new PageReference('/' + KARId );
    }
}