Problem with ok_code in BDC

Dear Gurus,

I have written a BDC program for a tcode. While doing the recording, we have to select a line and then press change button to change the value of articles. This selection mode is ok_code ' =CHAN'. But when I am running the program, this ok_code is not working. A pop up opens and says to select at least one row. If I manually select the row,then the rest of the program is doing fine. But i need to select the row automatically. Please help me.

With regards,

Rosaline.