Click on Select Box in TableGrid Example generates Null Pointer

[dschueler]

Apex script unhandled exception

Visualforce Page: /apex/warrior_serve__tableGridStandalone

caused by: System.NullPointerException: Attempt to de-reference a null object

Class.warrior_serve.TableGridController.doHandleSelection: line 272, column 1

[rsoesemann]

@dschueler could you solve this? Would you mind merging you solution back?