function winshow(url,winname,w,h){  
  if(w==null)
    w = 800;
  if(h==null)
    h=600;
  var newwin = window.open (url,winname,"height="+h+",width="+w+",top=0,left=0,toolbar=no,menubar=no,scrollbars=yes,resizable=yes,location=no,status=no");
  newwin.focus();
}