How to use Ajax Validator Collout Extender

Steps:-

Step 1 : Insert any validation control with textbox
Step 2 : Insert Validator Collout Extender with validation control from the Ajax Control Toolkit
Step 3 : Set the property of the Validation control : ControlToValidate,ErrorMessage,SetFocusOnError=True,Display=none and Give the proper name to the validation control
Step 4 : Set the ValidationControlID into the Validator collout Extender Property TargetControlID