How get contentplaceholder id using javascript

Hi friends

I need to get contentplaceholder id and assign to the variable. But i can't take

contentplaceholder id using javascript. In alert message it gives null.This is my

Code..

function ShowContentOne()
{
var elemId=document.getElementById('<%=ContentPlaceHolder2.ClientId%>');

elemId.style.display='block';
elemId.style.visibility='visible';
}

I hope ur's reply.

Thanks

Is ContentPlaceHolder2 an HTML element, an object on the serverside, a javascript prototype, or something else entirely?

Could you also give us ore information (ie. how/when is this function being called)?

Actually i am using master page and multiple content page. I have two link. Each link have one div. This links are placed in master page. One div1 is placed in content page 1 and another div2 is placed in content page2. While i give "set as start page" from mouse click while running, i click link2. But exception caught. That is div2 is "null". Because i am running content page1. So in the first content page what function and what control is available its working. But in content page 2 if i put function and some controls are available, it shows undefined or null. But i give set as start page to content page 2 its working.But content one is undefined( that is control and function ). This is my problem. I need to refresh the page.So i dynamically visible from content 1 to content 2. So i need to take contentplaceholder id. This is reference id of master page. That's all.

I hope ur's reply.

Thanks

Is this related to your earlier thread? http://www.vbforums.com/showthread.php?t=541186

Unfortunately your current question isn't very clear to me. You seem to want to do something between two pages but I can't tell what, so show us the code. All relevant code, not just the javascript you're trying to use.

frmMasterPage.Master:
==================
<form id="form1" runat="server">

<asp:ScriptManager ID="scriptManager1" runat="server">

</asp:ScriptManager>
<script type="text/javascript" language="javascript">

function ShowContentTwo() //while set as start page is frmContentTwo.aspx
{

alert("from two content");
this.id="frmMasterPage";
alert(this.id);
var elemId=document.getElementById('<%=form1.FindControl("ContentPlaceHolder2").ClientID%>');
//var elemId=document.aspnetForm.frmMasterPage_ContentPlaceHolder2;
alert(elemId);

elemId.style.display='block';
elemId.style.visibility='visible';

alert("from master two");

call()

}

</script>

<div>
<asp:UpdatePanel runat="server">
<ContentTemplate>
<a id="anchorLinkOne" runat="server" href="javascript:void(0)" onclick="ShowContentOne1()" style="color: blue; text-decoration: underline;cursor:pointer">Div One</a>
</ContentTemplate>
</asp:UpdatePanel>
<br />
<asp:UpdatePanel runat ="server" >
<ContentTemplate>
<a id="anchorLinkTwo" runat="server" href="javascript:void(0)" onclick="ShowContentTwo()" style="color: blue; text-decoration: underline;cursor:pointer">Div Two</a>
</ContentTemplate>
</asp:UpdatePanel>
<br />

</div>
<div>
<asp:contentplaceholder id="ContentPlaceHolder1" runat="server">
</asp:contentplaceholder>
<asp:ContentPlaceHolder ID ="ContentPlaceHolder2" runat="server">
</asp:ContentPlaceHolder>
</div>
</form>

frmContentPageOne.aspx :
===================
<asp:Content ID="Content1" ContentPlaceHolderID="ContentPlaceHolder1" Runat="Server">
<div id="divContentOne" runat="server" style="display:none;background-color:Red;height:500px;width:500px">

</div>

</asp:Content>

frmContentTwo.aspx :
=================
<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder2" Runat="Server">

<div id="divContentTwo" style="display:none;background-color:Green;height:500px;width:500px">

</div>
</asp:Content>