asp.net - How do I pass a server control's actual client Id to a javascript function?

Question

I have the following textbox server control in my web page:

<asp:TextBox ID="txtZip" runat="server" onchange="ZipCode_OnChange(this, <%= txtZip.ClientId %>, txtCity, txtState);/">

When the page renders, it is built including the following:

<input name="txtZip" type="text" id="txtZip" onchange="ZipCode_OnChange(this, &lt;%= txtZip.ClientId %>, txtCity, txtState);" />

I'm trying to pass the text box's client IDas the 2nd param to this Javascript function:

function ZipCode_OnChange(txtZipCode, ClientId) {
    var ret;
    ret = WebService.GetCityAndState(txtZipCode.value, OnComplete1, OnError, ClientId);
}

How do I get it to, on the server, evaluate the texbox's control and to pass that literal string to the Javascript function?

Answer 1

Put the <%= txtZip.ClientId %> between single quotes, to be like this:

'<%= txtZip.ClientId %>'


<asp:TextBox ID="txtZip" runat="server" onchange="ZipCode_OnChange(this, '<%= txtZip.ClientId %>', txtCity, txtState);" />

Update

Please check this article: http://www.jagregory.com/writings/how-to-use-clientids-in-javascript-without-the-ugliness/

Also I like this answer