Unexpected runtime error

The runtime has encountered an unexpected error.

Error source

Page Name:/xp_ZStandBrunnen.xsp
Control Id: _id41

Exception

Error while executing JavaScript action expression
Script interpreter error, line=6, col=58: 'doc' is null

JavaScript code

   1: if(document1.isNewNote()){
   2: 	var db:NotesDatabase = session.getDatabase("", "WGWS\\WasserGeno.nsf", false);
   3: 	var view = db.getView("($lookuplastZaehlerstand)");
   4: 	var doc:NotesDocument = view.getFirstDocument();
   5: 	
   6: 	getComponent("BrunnenI_letzte_Abl").setValue(doc.getItemValueInteger("BrunnenI_Aktuell"));		
   7: 	getComponent("BrunndenI_StundenVor").setValue(doc.getItemValueInteger("BrunndenI_Stunden"));
   8: 	getComponent("BrunndenIII_StundenVor").setValue(doc.getItemValueInteger("BrunndenIII_Stunden"));
   9: 	getComponent("BrunndenIII_Stunden").setValue(doc.getItemValueInteger("BrunndenIII_Stunden"));
  10: 
  11: 
  12: 	var tmptime:NotesDateTime = doc.getItemValueDateTimeArray("Datum")[0];
  13: 	time=tmptime.toJavaDate();
  14: 	getComponent("Datum_letzteAbl").setValue(@Text(tmptime.getDateOnly()));
  15: 
  16: }

Stack Trace