Validating dropdownlist in 2 0
Validation Controls Required Field Validator Control: The Required Field Validator control is used to ensure that fields that must be populated with data are, indeed, populated with data.
This control can be used with virtually any data entry controls, such as Text Box, Drop Down List, and Check Box.
Setting the property to None prevents the control from being displayed inline.
Fore Color: Use this property to set the color of the inline error message when validation fails.
However, for those browsers that support Java Script, the validation controls can perform client-side validation as well as server-side validation.
Client-side validation does not require a postback for validation to occur, resulting in a richer user experience.
Use the Dynamic setting when you want to avoid the control occupying blank space.
Enable Client Script: Not every browser supports Java Script, and even browsers supporting it might have it disabled.