XmlNode question...

Ok, tonights question of the evening is this...

I have a method which takes an XmlNode as a parameter.  This method then proceeds to process the information in the XmlNode but there's one particular node that "could" be present.  I'm trying to do a check against null on the node, but I keep getting object not set to refernce of an object...which I can understand.  Is there an easy way to check if this node exists and if so do something with it?  I'm looking through MSDN and must be just missing it.

Anyone got any suggestions?