Unexpected runtime error

The runtime has encountered an unexpected error.

Error source

Page Name:/Blog.xsp

Exception

Error while executing JavaScript computed expression
Script interpreter error, line=2, col=38: [TypeError] Exception occurred calling method NotesView.getDocumentByKey(null) null

JavaScript code

   1: var tempView:NotesView = database.getView("D6plinks");
   2: var tempDoc:NotesDocument = tempView.getDocumentByKey(param.entry);
   3: return tempDoc.getItemValueString("entryTitle") + " :: " + applicationScope.blogName

► Stack Trace