Output determination for purchase order

Dear friends,

Please help me, how to create condition record for both printout and email for output determination of standard PO.

I have created condition record through MN04 for Purchase order with medium(external send) and it worked.

I also need to create condition record for printout. Because Client wants to select either email,fax or printout. They will select whatever sending option.when i tried to create condition record for medium(1-printout).I got an error " The condition record entered already exists". So i tried to change that condition record,but i got here also error as "The condition is being processed in the current session".

Please help me to set up condition record for both mail and printout for standard PO.

Thanks