Alternative to Combo Box & List Box

[mtagliaferri]

Hi all, I am trying to avoid to use a Combo Box & a List Box because of the way the records are stored in the table, I only need to verify that the user does not enter a 3 letter code that is not contained in a specific table (I have a table of countries with the 3 letter code example if the user types ESC instead of ESP an error appears) Is it possible to use the after update to verify the contents against a table? if so hoe can I achieve this?
Thanks

 

[Gasman]

You could use a Dlookup for the value If not found display error message and stay in control.?

 

[BlueIshDan]

Why wouldnt you use a combo box that displays the distinct codes to select from?

Source: "SELECT DISTINCT code FROM table"

 

[mtagliaferri]

Thanks for the suggestions, the reason I want to avoid combo boxes is because I am applying the change to an existing DB, therefore in the table I have 3 letter codes, by using a combo box I will have future entries with reference to the primary key in the table.
after every entry within the data in the table will be only the 3 letter code and no numeric values.
Hope this makes sense.....attached there is a sample

 

[mtagliaferri]

I have used the LookUp option and created the table through the lookup Wizard option, selected the table and inserted ICAO Code, I then changed the option to text box and this is when the dataType in the table has changed to numeric therefore when opening the form it will only accept numerical values (1 to 40 which are the number of records) why has it changed to numeric?