Break Point is not triggering in the Class Method

Hi,

I need to Debug the method in the Abap class in the Task. And i have tried all the possible thing.

1) First i changed the method in Background to Foreground.

2) In the Class Method i wrote DO and ENDO statement and put a External Breakpoint.

3) Then i checked in the SM50 i can't able to see my Class method from where i can able to set the Debug.

What will be the reason ?????????

Kidnly suggest.

Regards,

Sadiq K