how to convert total amount into words in sap script in ZMEDRUCK form

Hi ABAPers,

    How to convert total amount into words in purchase order form. My requirement is that In ME23N when we click on print preview button in Purchase Order total net value amount comes in words format using HR_IN_CHG_INR_WORDS function module.

   What i have done is i have copied MEDRUCK as ZMEDRUCK . i have written  sub routine but i am not able to get the proper result in footer window i need to show the amount in words format.

please can you help me out how to write sub routine and how to use it sap script. Thanks in advance....

Thanks & Regards,

VInay Kumar.