Field Exits in ECC 5.0

Hi Friends,

I have a problem in Field exit.

We have upgraded from 4.5b to ECC 5.0 and as you know in Ecc 5.0 field exits are not there ,

So by using this program RSMODPRF i have activiated the field exits but it is not activating ,

Can any one tell me how to go with it .

Please help me ..

Thanks

Venkat