Validation Control in asp.net run at client side or server

Asp.Net validation controls perform the validation in  client side as well as server side. So always use asp.net validation controls.The validation is first done client side to prevent a
 wastefull trip to the server when the data is know to violate the validation
 rules. Assuming the data is good (or seems to be), the validation is again
 performed on the server to catch any spoofing attempts by the client.

Hi Salman,

They run at client-side :)