function launch_site() {

url = "preload.html";
 
screenWidth = screen.availWidth;
screenHeight = screen.availHeight;

popupWidth = 950;
popupHeight = 580;
 
leftPos = screenWidth/2-(popupWidth/2);
topPos = screenHeight/2-(popupHeight/2);
 
 site = window.open(url,'common1','toolbar=no,location=no,status=no,menubar=no,scrollbars=no,width='+popupWidth+',height='+popupHeight+',left='+leftPos+',top='+topPos+',resizable=no');
 site.focus(); 
}