Validation Error Messages
Error messages provide important information to a user, so for the best results, modify the default messages to provide as much information as possible.
The following validation methods allow custom messages:
The default error message for a regular expression validation method says: "Field item does not match any of the given expressions."
This default message does not provide information specific to the regular expression for the user. As a result, they might not know how to fix the problem.
For example, you configure a regular expression validation and define the layout of a customer number to contain 7 digits followed by 2 letters. Modify the error message to say: "The Customer Number entered does not meet the required format of 7 digits followed by 2 letters. Please try again." The modified error message describes both the problem and the solution so that the user knows how to correctly validate the field.
If necessary, you can also localize your error messages.