only allow English characters and numbers for text input

Question

Live Demo: http://jsfiddle.net/thisizmonster/DveuB/

How can I change this so that the input only allows the characters A-Z, a-z, 0-9 while typing, without using a re

Answer 1

You can do something like this: http://jsfiddle.net/DveuB/1/

Then it's only 0-9, a-z and A-Z

$(function(){
    $("#user").keypress(function(event){
        if ((event.charCode >= 48 && event.charCode <= 57) || // 0-9
            (event.charCode >= 65 && event.charCode <= 90) || // A-Z
            (event.charCode >= 97 && event.charCode <= 122))  // a-z
            alert("0-9, a-z or A-Z");
    });
});

Update: http://jsfiddle.net/DveuB/4/
To prevent what @mu is talking about:

$("#user").keyup(function(event){
    if (event.altKey == false && event.ctrlKey == false)
        if ((event.keyCode >= 48 && event.keyCode <= 57 && event.shiftKey== false) ||
            (event.keyCode >= 65 && event.keyCode <= 90) ||
            (event.keyCode >= 97 && event.keyCode <= 122))
            alert("0-9, a-z or A-Z");
});