Accessing .cs file..

Hello All,
I am presently working on a developed website and want to add some functionality to it.

I have a file called AssetPreview.ascx and the code behind the file as AssetPreview.ascx.cs

Now,

i added something to the ascx file like,

<a id="test" onclick = "temp()" runat="server" >Click here to download the file</a>

and so i added the method temp in the AssetPreview.ascx.cs as,

public void temp(object sender, EventArgs e)
{
//some functionality
}

Is this is correct way to do this..because when i click that link i am getting an run time error saying

Microsoft JScript runtime error : Object Expected

should i do anything else ???

Can any 1 please help me...