VL01N : Text field mandatory

Hi All,

I have one urgent requirement. In VL01N Transaction ( Create Outbound Delivery with Order Reference ) , i want to make header details for R.R./G.C.Note number mandatory. The path for Header Details is : Goto -- > Header -- > Text, then header texts appears in the left side. In that R.R./G.C.Note number should be mandatory.

Please tell how to do that.

Regards.

Ulhas