var win_count=Math.floor(10000*Math.random());

function popup(url)
{
  var width  = Math.round(screen.availWidth*0.8);
  var height = Math.round(screen.availHeight*0.8);
  var DemoWindow, left=0, top=0;
  if (document.all || document.layers)
  {
    left = Math.round((screen.availWidth-width)/2);
    top  = Math.round((screen.availHeight-height)/2);
  } 
  
  DemoWindow=window.open(url,"DemoWindow"+win_count,"height="+height+",width="+width+",scrollbars=1,resizable=1,menubar=0,status=1,left="+left+",top="+top+",screenX="+left+",screenY="+top);
  if (DemoWindow)
  {
   DemoWindow.focus();
   DemoWindow.resizeTo(width,height);
   DemoWindow.moveTo(left,top);   
  }
  return DemoWindow;
}