how to validate a registration page at client side

[eluser]bigtony[/eluser]
[quote author="rogierb" date="1253115677"]Use javascript to validate client side.

Try http://www.google.com/search?q=validate+...javascript
There are plenty of examples out there[/quote]
But be aware that hackers can easily bypass client side validation, so server validation is much more secure. But you can still use client side checking with javascript as well for other reasons (e.g. capturing errors early to reduce server load).