onload event for child window

[ng]

function w1open(){
alert("window loaded");
}
function wackOpen(){
var
my_window1=window.open('http://www.yahoo.com','','left=700,top=700','dependent=yes');

my_window1.onload=w1open;
}
wackOpen();


1. onload event is never captured..or by the time its get set the page
is loaded.
2. I am getting security issues if i use
my_window1.document.readyState.
3. Is there not way to check whether childwindow is loaded or not.
I have been through many threads in this group but none have a
solution. please help me out