var isIE = (navigator.userAgent.indexOf("MSIE")!=-1); 

// check for XPath implementation
if(!isIE) {
   // prototying the XMLDocument
   XMLDocument.prototype.selectNodes = function(cXPathString, xNode) {
      if( !xNode ) { 
        xNode = this; 
      } 
      var oNSResolver = this.createNSResolver(this.documentElement)
      var aItems = this.evaluate(cXPathString, xNode, oNSResolver, 
                   XPathResult.ORDERED_NODE_SNAPSHOT_TYPE, null)
      var aResult = [];
      for( var i = 0; i < aItems.snapshotLength; i++) {
         aResult[i] =  aItems.snapshotItem(i);
      }
      return aResult;
   }

   // prototying the Element
   Element.prototype.selectNodes = function(cXPathString) {
      if(this.ownerDocument.selectNodes) {
	     return this.ownerDocument.selectNodes(cXPathString, this);
      }
      else{throw "For XML Elements Only";}
   }


   // prototying the XMLDocument
   XMLDocument.prototype.selectSingleNode = function(cXPathString, xNode) {
      if( !xNode ) { xNode = this; } 
      var xItems = this.selectNodes(cXPathString, xNode);
      if( xItems.length > 0 ) {
         return xItems[0];
      }
      else {
         return null;
      }
   }
   
   // prototying the Element
   Element.prototype.selectSingleNode = function(cXPathString) {	
      if(this.ownerDocument.selectSingleNode) {
         return this.ownerDocument.selectSingleNode(cXPathString, this);
      }
      else{throw "For XML Elements Only";}
   }
}