Hi Mohan,
If you want to use the wild character use like statement.
concatenate gv_customername '%' into gv_customername.
concatenate gv_customernumber '%' into gv_customernumber.
SELECT SINGLE ebeln lifnr aedat FROM ekko INTO (gv_request, gv_supplier, gv_creationdate)
WHERE ebeln = gv_request_number AND
verkf like gv_customername AND
telf1 like gv_conactnumber OR
( aedat = gv_fromdate OR aedat = gv_todate ).
Also share the screen shoot of the dump.
Regards
Rajkumar Narasimman