Dom parsing in android

i have parsed xml using dom parser,but when the xml element contains no value it throws null pointer Exception.how to check this?...
here my code

NodeList TrackName1 = fstElmnt2.getElementsByTagName("Artist_Name");    
 
 
                     Element TrackElement1 = (Element) TrackName1.item(0);
 
                     TrackName1 = TrackElement1.getChildNodes();
                      result=result+((Node) TrackName1.item(0)).getNodeValue()
 
                      String  Artistname=((Node)TrackName1.item(0)).getNodeValue();
 
 
 
                                             }
 

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