Menu exit implimentation problem in se38

Hi expert

I have got the menu exit name .

In my knowledge this enhancement  have two part

->Menu exit(To add menu text)

->Function Exit(To add the logic after the clicking this menu what will happen)

I have added menu text through Menu exit .

For applying the functionality ,I did double click ,then it went to function module 'EXIT_SAPLWBABAP_010' .It has a include program strating with ZX...

Now i am trying to create this but it shows error .

"Program names ZX... are reserved for includes of exit function groups"

Message no. DS027

Thanks & Regards

Rajesh