Adding rows in visualforce page in PageBlocktable dynamically - salesforce

Question

i am creating a dummy visualforce page whose code is
<apex:page controller="sampleCon">
<apex:form>
<apex:pageMessages id="message" />
<apex:pageBlock>
<apex:pageBlockTable value="{!wrap1}" var="item" id="hello">
<apex:column headerValue="String" value="{! item.x}"></apex:column>
<apex:column headerValue="Action"><apex:commandButton value="{!if(item.i == size-1,'Add','Delete')}" onclick="AddOrDelete({! item.i});" rerender="message"></apex:commandButton></apex:column>
</apex:pageBlockTable>
</apex:pageBlock>
<apex:actionRegion >
<apex:actionFunction name="AddOrDelete" action="{!addElement}" reRender="message,hello">
<apex:param value="" name="fieldName" />
</apex:actionFunction>
</apex:actionRegion>
</apex:form>
</apex:page>
and the controller code is
public class sampleCon {
public List<Wrapper> wrap1{get;set;}
public Integer size{get;set;}
public sampleCon(){
wrap1=new List<Wrapper>();
wrap1.add(new wrapper(0));
size=wrap1.size();
}
public PageReference addElement(){
size=wrap1.size();
System.debug('Hello ji'+Apexpages.currentPage().getParameters().get('fieldName')+'size is'+size);
Integer i=Integer.valueOf(ApexPages.currentPage().getParameters().get('fieldName'));
if(i == size-1)
{
wrap1.add(new wrapper(size));
size++;
}
return null;
}
public class wrapper{
public integer i{get;set;}
public String x{get;set;}
public wrapper(Integer p){
i=p;
}}
}
what i am trying is the last row button label should be Add and other button label should be Delete when i press add button a new row is added and the label should be changed acordingly for this i am adding row but it is not working as expected
initial page screenshot is
when i press add button screen look like this.
when i again press the Add button screen is looking like first screenshot.i was expecting that one more row will be added when i click add button in above screenshot.can any one please tell why only one row is showing when i click add button in second screen shot and how to correct it that when i again click on add button on above screen one more row will be added instead of showing initial screen.

Answer 1

I would suggest you take a list at below post:
http://boards.developerforce.com/t5/Visualforce-Development/Add-Row-functionality-in-VisualForce/m-p/358921
Hope this helps.