data validation in two tables

[mrdx07]

validate 1st table to 2nd table if 1st table records exist in 2nd table the record will not be recorded.(validate that say " the record is already exist in table2)

table1 and table2 has same filds

 

[trentham]

If Dcount("*", "table2", "key=" & keyvalue) > 0 then

msgbox "Record already exists", vbOKOnly, "Validation"
exit sub
​

End If

Or are you wanting something more than this?