function calcHeight(elem)
{
        //find the height of the internal page
        var the_height=500;
        var padding=1;//to avoid the scroll bar
        try
        {
                if( elem.contentWindow && elem.contentWindow.document)
                {
                        the_height=elem.contentWindow.document.body.scrollHeight;
                }
        }
        catch(e){}
        //change the height of the iframe
        elem.height=the_height +padding;
}