I have modified a standard user-exit SAPMV45A screen number 8309. It was initially a sub-screen, i changed it to normal screen and activated it. It gave run-time error in VA02. So , I again tried to change the screen type from normal to sub-screen, but it is giving an error message ' delete the name fcode of the ok_code first ' . I didn't change any ok code and there is a function code in element list which is non-modifiable. How shall i correct this error. Please suggest.