IE 5.5 or not?

[searain]

I need to see if a browser is IE5.5 or better, otherwise, I want to pop up a alert window. How to do that?

Thanks!

[pyro]

You'll have to use JavaScript (cause of the alert)...

[superwormy]

You can check $_SERVER['HTTP_USER_AGENT'] but note that it can be easily spoofed and isn't all that reliable...