Javascript vs ASP.NET validation, which one to choose?

Question

Concerning validation,

1. Are javascript and ASP.NET validation used for the same purpose?

2. If yes, which one do you recommend? Please provide a simple explanation.

Thanks

Answer 1

Always validate on the server. Client-side validation is only to make the user experience more pleasant. Which is important, but only important as far as the experience goes. Validation on the client is not important at all for the purposes of validation, because anything running on the client machine can be compromised or bypassed by the same client.