/**
  *  浏览器兼容性代码
  *  Copyright 2006 AEware company
  *  http://www.passbay.com
  *  author: hawk
  **/

    // check for XPath implementation
    if( document.implementation.hasFeature("XPath", "3.0") )
    {
       // 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";}
       }
    }

    // check for XPath implementation
    if( document.implementation.hasFeature("XPath", "3.0") )
    {
       // 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";}
       }
    }