Text for validation

Hello everyone,

I am having a parameter field and a internal table. I am trying to delete all the entries from itab(with out header) other than whats there in parameter field. Both the fields or of type cdpos-fname (Field name). But iam unable to achive it. In debugging i checked and the text in parameter field is changed to <b>upper case</b> even though i gave in lower case.

I am giving parameter text as -

W/Tax code.

I have checked the itab and it has W/Tax Code entries. So i did the validation as below..

if not p_fname is initial.
delete itab where fname ne p_fname.
endif.

But its not deleting any even though there are entries present.

Where i am going wrong. Can anyone help me.

Regards