File save failed at Save as Unicode; System thrown Error:Object reference not set to an instance of an object.

---Application Information----
AppTitle: Akshara Indic Script Generator
Build: 0.0.0.9
Environment: Developer Beta
---End of Application Information----

---Usage Information----
Date/Time : 3/13/2008 10:43:09 AM
User: kiran.chand@kiran.chand.info
Reply To: kiran.chand@kiran.chand.info
Remarks: chumma oru test!
Friendly Description: File save failed at Save as Unicode
---End of Usage Information----

---------Error Trace------------
System.NullReferenceException: Object reference not set to an instance of an object.
at Akshara.WinUI.MainWindow.SaveUnicode_Click(Object sender, EventArgs e) in C:\Documents and Settings\kiranchands\My Documents\Visual Studio 2005\Projects\Transliteration\TransliterationUI\MainWindow.vb:line 142

---------End of Error Trace------------