F4 help -- on editable alv field.

<b><i>Hi ABAPers,</i></b>

<i><b>I want to incorporate F4 help with the editable field of my ALV report.</b></i>

The editable field is type of IHPA-PARNR.

At present user is able to enter value at this field. but the requirement is to give F4 help there.

I am not using the OOPs alv.

<i><b>Please suggest me

Thanks in advance

Regards

Debjani</b></i>