to open a new little window with no max button

[hajer]

I have two questions about js 1.2 and I.E 5.0;
1) I want to open a new little window with no max button ...
The function window.open() can not help me...

2) I want to open this window in the middle of the parent window...
so i used this code:

x = window.screenX + ((window.width - 300) / 2);
y = window.screenY + ((window.height - 160) / 2);
alert (window.width);
alert (window.screenX);

window.screenX, window.width et window.heigth return the value "Nan"...

Please, I need some help...
Grazie, thank you
Ciao, Bye