postback causes jscript error?? help

[NervousRex]

I have a couple checkboxes on my form, I need them to
fire the checkchanged event when they are clicked. From
what I understand, the only way to do this is with
autopostback set to TRUE.


When I do this, the code the control adds to the page
causes an error

"Microsoft JScript runtime error: Object doesn't support
this property or method"


Here is the code it adds, note the line that errors


<script language="javascript">
<!--
function __doPostBack(eventTarget, eventArgument)
{
var theform;
if (window.navigator.appName.toLowerCase
().indexOf("netscape") > -1) {
theform = document.forms["Form1"];
}
else {
theform = document.Form1;
}
theform.__EVENTTARGET.value =
eventTarget.split("$").join(":");
theform.__EVENTARGUMENT.value =
eventArgument;
theform.submit(); <======ERRORS HERE!!!
}
// -->
</script>



My Specs:
VS.net 2003
v1.1 framework



Any help is appreciated!!

NRex