Asp .NET Button - OnClientClick=“return function()” vs OnClientClick=“function()”

Question

In an asp.net user control I have a button:

Answer 1

First : the client side runs (OnClientClick)

Then - the server side.

But

The client side code can prevent execution of server side by return true/false.

usually we use it for validation , before submitting to server.

Do this and your server side will ( without hacking) never work :

OnClientClick="return false;"