var _Doc = app.activeDocument;  
        var _Root = _Doc.xmlElements[0];  
          
        var _xpathElements = _Root.evaluateXPathExpression (".//image");  
          
        for ( var c = 0; c < _xpathElements.length; c++ ) {  
try 
{ 
 
                …   
} 
catch (error) 
{ 
  alert(error.message +"\n" + error.line.toString()); 
} 
            }