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"

>>61
When someone is walking around covered in in his own vomit, who is the greater dick: the person who helps him clean up, or the person who pretends there's nothing wrong with walking around covered in your own vomit?