Cursor position(Enter function) not working in custom screen of LM03/LM05

Hi SAP GURUS,

For including Batch verification filed,we have copied 2212 standard screen and created a sub screen with 9212, while copying the screen 2212 we have removed the OK_CODE.

we have included logic in user exits (EXIT_SAPLLMOB_170 & EXIT_SAPLLMOB_480,After executing the transaction lm03, in source screen after scanning source bin, the cursor is not moving to next field.

please help me what is the logic i need to include in the user exits, to move the cursor automatically from one filed to another while scanning.

Thanks in advance.

Pavan kumar kuppala.