quantity field error

Hi all,

i am working on upgrade project ,from ecc5.0 to ecc6.0,i am getting error like

QTY_TAB-ATP must be a character-type field (data type C,N,D,or T

its already decleared in the program atp like mdps-mng04

ATP is an quantity field ,in the table its decleare in data tyep is p, and length of the field is 13.

i decleared like below

DATA: atp(13) type p. its working fine ,if i decleare C,N,D the field value is not coming in out put.

please suggest me how to do further for this error,is it correct declearation are i need to change.

Regards,

Madhu