Customer exit for cost center group based on cost center(user entry)???

Hi Gurus,

My requirement Is to display cost center group when the user keys in Cost center.

So i created a customer exit variable on cost center group.

This is the code in CMOD... though there is no error, it doesn't seem to work.

I have attached the file.

Cost center group variable- 'interval option'

Cost center variable- 'selection option'

Regards,

Amala