var newwindow = ''

      function popitup(url) {
      if (newwindow.location && !newwindow.closed) {
          newwindow.location.href = url; 
          newwindow.focus(); } 
      else { 
          newwindow=window.open(url,'htmlname','width=930,height=620,resizable=1');} 
          newwindow.document.images[0].alt = "Copyright text"; 
      }

      function tidy() {
      if (newwindow.location && !newwindow.closed) { 
         newwindow.close(); } 
      }
// Based on JavaScript provided by Peter Curtis at www.pcurtis.com