duplicate values in dropdown:MOST URGENT

[paritosh_a]

I am getting the error in a grid which has combobox.
This combobox allows only to select unique values from the list.
Whenever i selects the same value in another combo which is already selected in the grid, its shows the popup with the below message and makes us not to click anywhere else in the application.

"The changes you requested to the table were not successful because they would create duplicate values in the index, primary key, or relationship.Change the data in the field or fields that contain duplicate data, remove the index, or redefine the index to permit duplicate entries, and try again".


And when i delete the duplicate value selected in combobox it shows the popup with this message "Index or primary key cannot contain NULL value".

I simply wants this :
Whenever user selects duplicate value, message must be displayed and user comes out from that combo.

Please help urgently.

 

[neileg]

The Access mesaage suggests this combo is attached to a field which is either a primary key of a field with an index set to No Duplicates. It would be strage to have a combo on a primary key field. Please explain more.

 

[paritosh_a]

combobox in grid

This combobox is in grid.
when i select some value suppose 'A' from combo,new combobox is displayed below to select another value.
if i select the same value in this combo also e.g. 'A' it showed that error.
rowsource property has this value for this combobox 'SELECT CasinoheaderTbl.CasinoID, CasinoheaderTbl.CasinoName FROM CasinoheaderTbl; '.....controlsource is 'casinoid' which is a coulmn name in table with only three columns named 'playerid,casinoid,playercasinonumber'.

playerid and casino id are set as primary keys in this table.

 

[neileg]

playerid and casino id are set as primary keys in this table.

CasinoID is only a primary key in CasinoheaderTbl. In the other tables it is a foreign key.

Set out your tables and relationships for a fuller diagnosis