Cannot enter longer value in column

Hi all,

I added user column to form 139. This column has userdatasource ("re",SAPbouiCOM.BoDataType.dt_LONG_NUMBER,8). Now when i open this form and i want to add new value to this column i can enter only value which is length=1. Longer value cannot add. Where is problem.

Thanks

P.S.

Im sorry of my english