winWidth = 1000; // sets a default width for browsers who do not understand screen.width below
winheight = 647; // ditto for height

if (screen){ // weeds out older browsers who do not understand screen.width/screen.height
   winWidth = screen.width;
   winHeight = screen.height;
}
  
// this function calls a popupWindow where
// win is the page address i.e. '../page.htm'

function popupWindow(win){
  
  newWindow = window.open(win,'newWin','toolbar=no,location=no,scrollbars=no,resizable=yes,width='+winWidth+',height='+winHeight+',left=0,top=0');
  newWindow.focus();
}