window.opener.location in Safari 1.0 and IE 5.2

On Safari 1.0 and IE 5.2 window.opener.location seems not work!!!
Hi have a form with target _blank.
In the window opened by the form I try to do:
window.opener.location="url";
or
window.opener.location.href="url";
or
window.opener.window.location.href="url";
or
window.opener.document.location.href="url";
or
opener.window.location.href="url";

but doesn't work.

Please where I can find some information about compatibility of
javascript with these browser?