Timing Issue

For some reason this does not work. If I place an alert box in before the last line, it works fine. Also, is this the correct code to maximize a window?

Thanks

Code:

---

function f_Pic(str_data)
{
        var T = window.open('./hi.html','Window_PictureID','menubar=no,status=no,location=no,toolbar=no,hotkeys=no,resizable,width=screen.width,height=screen.height');
        T.resizeTo(screen.availWidth,screen.availHeight);
        T.moveTo(screen.width-screen.availWidth,screen.height-screen.availHeight);
        T.focus();

        T.document.imgMainPicture.src=str_data;
}

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