hi guys....

I am trying to add a feature in my page block table like a more column for choosing a list of salesorders. and for that I need a dropdown menu with multiselect functionality with checkboxes ....... here is code sample...

<apex:page controller="MultiSelectDropdownMenu">
    
    <script>
       
        function checkAll(cb){
        var inputElem = document.getElementsByTagName("input");
            for(var i=0; i<inputElem.length; i++){
                if(inputElem[i].id.indexOf("checkedone")!=-1)
                    inputElem[i].checked = cb.checked;
            }
        }
       
        function myFunction(id){
            alert(col +'----'+ id);
            document.getElementById(id).style.display= 'block';
        }

        function calcDedSecCCD(elm) {
            var eid = elm.id;
           
            document.getElementById(x).style.display= 'block';
        }
       
        function myFunction1(){
            //alert('bye');
            var x= document.getElementById('panel').style.display= 'none';
            document.getElementById('flip').style.display= 'block';
            document.getElementById('flip1').style.display= 'none';
        }
       
    </script>
    <apex:form id="main">
    <apex:pageBlock id="pb" >
    <apex:pageBlockTable value="{!selectedSOrders1}" var="s" id="pbt">
    <apex:column value="{!s.name}" />
   
    <apex:column id="pbtc" headerValue="TAX" onclick="calcDedSecCCD(this)">
        <div id="p" style="border:1px solid black;width:125px;height:auto;padding:5px;">
            <div id="panel"  style="width:125px;height:auto;padding:5px;display:none;">
                <hr></hr>
        <apex:dataTable id="pbdt" value="{!SalesOrders}" var="a" cellpadding="5">
            <apex:column >
            <apex:facet name="header"> <apex:inputCheckbox >
            <apex:actionSupport event="onclick" action="{!GetSelected}" onsubmit="checkAll(this)" rerender="Selected_PBS"/>
            </apex:inputCheckbox></apex:facet>
            <apex:inputCheckbox value="{!a.selected}" id="checkedone">
            <apex:actionSupport event="onclick" action="{!GetSelected}" rerender="Selected_PBS"/>
            </apex:inputCheckbox>
            </apex:column>
            <apex:column headervalue="All" value="{!a.acc.Name}" />
        </apex:dataTable>
         </div>
        </div>
    </apex:column>
    </apex:pageBlockTable>
    </apex:pageBlock>
    <br/><br/><br/>
    <apex:pageBlock >
    <apex:pageBlockSection Title="Selected Orders" id="Selected_PBS">
    <apex:dataTable value="{!SelectedSOrders}" var="s" columnswidth="50px,50px" cellpadding="4" border="1">
        <apex:column headervalue="Name" value="{!s.id}" />
    </apex:dataTable>
    </apex:pageBlockSection>
    </apex:pageBlock>
    </apex:form>
</apex:page>

so this is not giving me the id of component from where I clicked the colum of row.

now you can see the hierarchy so if anyone have any solution than plz let me know...