if user selects wrong value, display message

Hi all,



I have a field that is pre filled in with a value. The name is "Business"

Then there is a combo box with various values. If the user would select a value that does not match with values that can be selected if in "business" a value is selected, it should show a message that the selection is wrong and user needs to select the correct one.



Example:

If in the field "Business" the value "Food" is selected, then the possible values to be selected in the combobox would be: Fruit or Meet or Fast Food. If the value in "Business" would be "Wood" only selections could be made: Talble or Chair or Cabinet.

So, if a user select "Food' in "Business" and in the combo box "Chair", it should show a message that the wrong selection was made and don't let them use the wrong one.



Any help in getting this solving this?



Greetings.

if user selects wrong value, display message