Introduction Custom validator performed user defined validation on an input control. This control allows you to define your own validation. the property ClientValidationFunction sets the name of function or script that will do the validation. This function takes two parameters. The first argument source identifies the source control to validate. The second argument hold the data to validate. The custom validators does not checks for whether there is some input in the control to be validated so you must need to attach a RequiredFieldValidator in addition to a CustomValidator control, if you require that certain data should be present in the validated field. So you must provide a server side validation function for a CustomValidator control. Here we are discussing an example in which we are implementing custom validation control Event.
In this article you learned how to implement custom validation control Event.