Its really urgent

hii all

Among the 4 cols 'Selection','Hide','Inversion','Field only known....',only the hide field is enabled while other cols are disabled.I would like to mention that I have enhanced the datasource(extract structure) 0fi_ap_4

and only enhanced fields are enabled for 'selection', while the existing fields appear grey, thus i am unable to select even company code and fiscal year/period.If u can help.

If i am unable to convey u my message then plz let me know.Its really urgent.