Ajax Postback issue

[engsrini]

Hi, I am using asp.net 2.0, trying to create chat application. I am copying the user entered text to a asp.net textbox using the following java script function

    document.getElementById("TextBox1").value= "chat message entered by user";	
userid = location.search.substring( 1, location.search.length );
url = 'Chat.aspx?action=chatmsg&u=' + userid ;

req = getAjax();

req.onreadystatechange = function(){
	if( req.readyState == 4 && req.status == 200 ) {
		updateAll();
	}

}	
req.open( 'GET', url, true );
req.send( null );

with the following asp.net textbox definition

<asp:TextBox ID="TextBox1" runat="server" AutoPostBack =false ReadOnly=false ></asp:TextBox>

and i am handling the ajax postback @ chat.aspx like this chat.aspx's page load method

protected void Page_Load(object sender, System.EventArgs e)
{
string chatMsg = TextBox1.Text;
}

But the problem is i always see the TextBox1.Text as empty instead of "chat message entered by user" which i copied thru javascript function, but i can able to see in internet explorer that the TextBox1.Text gets updated when i call postback. I put alert before calling chat.aspx like this

alert("TextBox1 text VALUE = "+document.getElementById("TextBox1").value);

it is also showing the updated value, but i could not able to see in the codebehind (page_load method) But if i do any postback thru button click, i can able to see the updated vlaue of TextBox1.Text Can somebody help me out.. what went wrong on this? Thanks Srini

[Herman T Instance]

If you run your app and then watch the html source via your browser you will find the ThextBox1 control has some additions. Put that one in your getElementByID().