How should I use showModalDialog() ?

Junior WebHelper Joined: 23 Dec 2003 Posts: 4

I'm having a big problem with the function showModalDialog(): every time I call it with a returnValue in the Dialog, it returns undefined. What's the problem?

For example, I have this:

<body onload=a()>
<script language=jscript>
function a() {

var vReturnValue=""

vReturnValue=showModalDialog('about:<input type=button onclick=\'returnValue=\"aaaaaaa\";window.close()\'>')

alert(vReturnValue)

}
</script>
</body>

And it alerts "undefined" instead of "aaaaaaa". Well, I guess there's something wrong with my way of calling the function; if not, then what is it? Please help me.

Thanks a lot.