windows phone 7 - AutoCompleteBox when empty entries -

I'm using this filter in my auto-comptebox.

  bool searchbird (string search, object value) {if (value! = Null) {AllBirds datasourceValue = Value as AllBirds; String name = Datasarvalue.primi_language; If (name toLower (). Start (Search. ToLower ())) True Return; } // If someone does not match, return false. return false; }   
 Everything is working fine when all entries have some value, but when there is an empty record, it is giving an error with blank exception (which is understandable) Does not come because there is no value). Try smth with more or more statements but still getting the same error.   
 
 
 And if more if u use not?  
 Add it later, may help  
  else {return false; }