Locking lookup fields in form

[rdev]

I have a table named tblShipmaster with fields
IMO_Num(Primarykey),Ship_Name,Vessel_type.
The Vessel_type field picks up value from a lookup field of a table called tblshipcategory
I have a related form to enter data in the tblShipmaster, the form is known as frmshipmaster.
After a few records are entered directly in the table . I go to the form frmshipmaster to enter few other records. However, in the form I can edit the field Vessel_type , this should not be possible for records I have already entered. when I am picking this field (Vessel_type) in other queries , I can edit the field for the related record. I should not be able to do this . How can I lock this

Thanks\
Dev

 

[HiTechCoach]

Dev,

No need to double post. See original post for replies.