// FCG 12/03/2010 - Estas funciones reimplementan selectSingleNode y selectNodes para que sean compatibles tanto con IE como con Firefox.

// 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";} 
} 
}