Santhi,
Thanks for the reply,
what I wanted is somewhat strange,

I want to raise TextBox1_TextChanged event(server side event) when user clicks on Button
at client-side codes(I mean I want to launch a server side event from the client side codes)

this is the tag I use in my ASP.NET page
<button id="mahdi" type="button" language="javascript" onclick="document.Form1.TextBox1.onchange();">

when user clicks on the button document.Form1.TextBox1.onchange() will be executed
so __doPostBack('TextBox1','') would be executed so there would be a postback but
when this postback occures just Page_Load fires other server side events like TextBox1_TextChanged doesn't fire.

_____________
Mehdi.
software student.