Clearing values out of the screen. --- URGENT

Hi,

I am adding a subscreen with a new field in MM01 via configuration. The new field is append to MARC structure. Now When create a material I am able to see my new field and able to enter the value. But this value is getting cleared when I come out of my custom screen. Meaning I am able to see my value only in my custom screen. So my value is not INSERTED in MARC table. As screen is added to the standard transaction insertion will be done by standard program.

As this new field is appended to the MARC table it will be global declared in the standard program. So I am not getting what have to be done.

Can anybody let me know about this?

Br,

Laxmi