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") == "external") {
     anchor.target = "_blank";
    }

}
}
window.onload = externalLinks;

//////////////

<a href="whatever" rel="external" title="whatever">Whatever</a>

<form id="search"...

<a href="#" onclick="document.forms['search'].submit();return false" title="Search">Search</a>

    	<input type="submit" value="Search" onclick="javascript:return text_validate()" />
   	<input type="reset" value="Reset" />
    	<input type="button" value="Show All News" onclick="javascript:return showAll();" title="Show all news button." />

Could be shown as:

        <a class="blockbutton" title="Search" href="javascript:document.search_form.submit();" onclick="javascript:return text_validate();">Search</a>	
	<a class="blockbutton" title="Reset" href="javascript:document.search_form.reset();">Reset</a>
	<a class="blockbutton" title="Show All News" href="javascript:showAll();">Show All News</a>

<script type="text/javascript">
  function doSubmit(){    
        document.getElementById("whatever").submit();
        return true;   
     }   
</script>

<a href="#" onclick="doSubmit();return false;" title="Search">Link</a>

  <!--[if IE]>
    Content
  <![endif]-->

  <!--[if lt IE6]> //lower than IE6
    Content
  <![endif]-->


and the XSL version

  <xsl:comment>[if IE 7]&gt;
    Content &lt;![endif]</xsl:comment>

<xsl:output method="xml" omit-xml-declaration="yes" encoding="us-ascii"/>