Hi Gita,
Got the problem.
Correct these two lines and all will be fine.
SELECTION-SCREEN COMMENT1(10) scr_pnam FORFIELD lv_name.
SELECTION-SCREEN COMMENT70(10) scr_pval FORFIELD lv_value.
See what I have changed and you will understand what you were overlooking.
Best of luck.
Saurabh