How can detect Opera?

[peterhou]

I want to disable people who use Opera,how can i detect Opera?
thanks

[fredmv]

You can just check for the existence of window.opera, but I don't get why you'd want to do such a thing.

[peterhou]

thank you for quick reply.
I'll use it Not in whole site,just some importent pages.

yours
peter

[peterhou]

Yes,it can detect Opera.but when I use die,the page still can load.How can stop load page:
if (window.opera) {
die ("...");
}

thank you

[peterhou]

One more thing:window.mozila can detect mozila?
thank you.
I want to disable mozila also.