RMA UDF number to auto-populate

Hi,

I use the Return document in draft mode as a work around for RMA functionality.

I created a UDF for the RMA number that needs to auto-populate a unique number.

I tried this formatted search: "Select MAX(T0.U_RMA)+1 from ORDN T0", but this only gave a unique number when the previous RMA was entered as a Return doc.

I was thinking that incorporating a date/time stamp into the number might be a way to make it unique.

Any help would be greatly appreciated,

Marli