<apex:page>
</apex:form>
<script>
$(document).ready(function{


});

function callfunction1(){
var value = $('.picklist1').val();
var text =$('select option:selected').text();
calldeliveryno(value, text);
}

function callfunc2();{
var value=$('.picklist2').val();
var text= $('select option:selected').text();
calllineitems(value,text);
}
function
</script>
<apex:Pageblock>
<apex:pageblocktable value="{!listrecord}" var="list">
<apex:column headervalue ="first picklist">
<apex:selectlist value="{!list.firstcolumn}" styleclass="picklist1 vareity " onchange="callfunction1();">
<apex:selectoptions value="{!forpicklist1}">
</apex:selectlist>
</apex:column>

<apex:column headervalue ="second picklist" id="column2">
<apex:selectlist value="{!list.secondcolumn}" styleclass="picklist2 vareity " onchange="callfunc2();">
<apex:selectoptions value="{!forpicklist2}">
</apex:selectlist>
</apex:column>

<apex:column headervalue ="Third picklist" id="column3">
<apex:selectlist value="{!list.thirdcolumn}">
<apex:selectoptions value="{!forpicklist3}">
</apex:selectlist>
</apex:column>



</apex:pageblocktable>


</apex:pageblock>
<apex:actionregion>
<apex:actionfunction name="calldeliveryno" action"{!passdelivery}" rerender="column2">
<apex:param name="delno" assignto="firstpicklistval" value="">
<apex:param name="delno1" assignto="firstpicklisttext" value="">
</apex:actionfunction>
</apex:actionregion>

<apex:actionregion>
<apex:actionfunction name="calllineitems" action"{!passlineitem}" rerender="column3">
<apex:param name="lineno" assignto="firstlineitemval" value="">
<apex:param name="lineno1" assignto="firstlineitemtext" value="">
</apex:actionfunction>
</apex:actionregion>

</apex:form>
<apex:page>