how to set cursor in a specific field

hi ABAPers

i have 5 fields in the screen

i want set the cursor in the 3rd field

how to set the cursor..

i have tried with

SET SURSOR FIELD wa_matnr.

and

SET CURSOR FIELD wa_matnr OFFSET 5.

i have given these two statements . but i didn't get the answer...

please give me the answer..

Regards

venkatesh