user-exit for delivery while assigning serial numbers(urgent)

hi all,

can u plz tell me the specific user exit for delivery (VL01n) while assigning serial numbers?

i am getting the serial numbers for material in database table OBJK .i am also getting these serial no.s in IQ01.

while doing delivery,i am going for extra-->serial number.at this time one screen for serial number is comming.those serial numbers which are stored in objk will transfer to this screen of delivery automatically.

for this , i want a specific user-exit for delivery so that i can transfer the serial nos from objk to that screen of delivery.plz suggest .(urgent )

any idea is highly appreaciated

Regards

pabitra