var winW = 630, winH = 460;

if (parseInt(navigator.appVersion)>3) {
 if (navigator.appName=="Netscape") {
  winW = window.innerWidth;
  winH = window.innerHeight;
 }
 if (navigator.appName.indexOf("Microsoft")!=-1) {
  winW = document.body.offsetWidth;
  winH = document.body.offsetHeight;
 }
}

winH = screen.height - 100;

if ((screen.width>=1024) && (screen.height>=768))
{
	if (winW < 960)
	{
	window.moveTo(0,0); 
	window.resizeTo(960, winH);
	}
}
else
{
	if ((screen.width>=800) && (screen.height>=600))
	{
		if (winW < 790)
		{
		window.moveTo(0,0); 
		window.resizeTo(790, 560);
		}
	}
}

<!-- If you're even lower than 800x600, then buddy, you're on your own. -->
<!-- Opera doesn't support resize events -->