function externalLinks() { 
 if (!document.getElementsByTagName) return; 
 var anchors = document.getElementsByTagName("a"); 
 for (var i=0; i<anchors.length; i++) { 
   var anchor = anchors[i]; 
   if (anchor.getAttribute("href") && 
       anchor.getAttribute("rel") == "nwin") 
     anchor.target = "_blank";
      
   else if (anchor.getAttribute("href") && 
     anchor.getAttribute("rel") == "cwin") 
   anchor.target = "cwindow";
   
   else if (anchor.getAttribute("href") && 
     anchor.getAttribute("rel") == "twin") 
   anchor.target = "_top";

   else if (anchor.getAttribute("href") && 
     anchor.getAttribute("rel") == "swin") 
   anchor.target = "_self";
   
 } 
} 
window.onload = externalLinks;