Try:
Parameter
resizable=yes|no
function popup() {
cuteLittleWindow = window.open("slidegallary.aspx", "littleWindow", "location=center,resizable=no,width=800,height=630");
}
Details about parameter:
resizable=yes|no|1|0
: Whether or not the window is resizable. Default is yes.
UPDATE:
Here, have a detailed look on
Window.Open feature[
^].