// should be called with the id of an iframe
function getHeight(the_id) {
    if( is_valid( 'string', the_id ) ) {
        var obj = document.getElementById(the_id);
        if( obj ) {
            //find the height of the internal page
            var the_height=obj.contentWindow.document.body.scrollHeight;
            //change the height of the iframe
            if( the_height ) obj.height=the_height;
        }
    }
}