IFRAME

Hi
I have a problem in javascript/HTML
I set the document.src property of IFRAME tag to a HTM file .
How I know that the htm file is fully read(opened or say status) to display its content into the DIV tag through document.innerHTML property.
<div id="divIE"></div>
<div id="divIECont">
<iframe name="my" scrolling="No" width="500" height="65%" frameborder="No" ></iframe></div>
</div>

i set the src property of Iframe with in a function "changeSrc()" and need to show the content of "plastic.htm" in the Div through function "show()"

var pp1;
function changeUrl(url)
{
document.all["my"].src = url;
pp1 = setTimeout("track()",500);

}

function track() {
document.write(my.document.onload)
if (my.document.readyState == ‘complete’) {
ddd();
}
else {
pp1 = setTimeout("track()",50);
}
}

function ddd()
{
divIE.innerHTML = my.document.body.innerHTML;
clearTimeout(pp1);


}

The content will show when the size of the file is not too large
But when the size of file is large and it will not loaded in 50 milliseconds then content will not appear.
so you know any property or method as we find the status of file (load completely or not) and then call the function "Show()" to visible the content in Div tag.