Web Browser Compatability

When doing a website, do you think it's right to be code for only certain browser (ie the most used browsers like Firefox & IE (latest ver)) and to just say to other users of browsers like Safari, IE 5 , "sorry you cant use this site"

We have web standards so that we don't need to code for a specific browser. It's the browser's responsibility to meet standards, not the web designer to implement hacks to work around half a dozen mutually broken browsers.