OnBeforeUnload And Submit() Together?

I have written a web application in .ASP with VBScript and JavaScript running against a SQL back end. Everything works great except my BeforeUnload() event:

<%'Add a script to save any unsaved data before the client leaves the page%>
<script language="JavaScript">
window.

function confirmExit()
{if (document.Client_Info_Page.Value_Changed.value == "true")
{if (confirm("This record has been changed. Press [OK] to save; [Cancel] to discard."))
{document.Client_Info_Page.submit();
alert("Changed and save");}
else
{alert("Changed and no save");}
}
}
</script>

<%'END Add a script to save any unsaved data before the client leaves the page%>
This code checks a variable to see if anything's been changed on the page and if it has, it asks the user if they'd like to save before exiting. The alert boxes are just to show the If/Then is working correctly (which it is) but the .Submit() function just gets ignored as the page exits.

Just to play, I made a java button and cut and pasted the submit() into and when that's clicked it submits with no problem.

Anyone know how I can get the onBeforeUnload to push a .Submit()? I've changed it to stop the exit and allow the user to save, but it would be so much smoother if it could be automatic.