html keycodes not working in firefox

Question

I have the following code:

function noNumbers(e)
{
    var charCode = (e.which) ? e.which : 
                 ((e.charCode) ? e.charCode : 
                   ((         


        

Answer 1

Why not handle the input event instead? This method will handle live changes via keyboard entry, cut, paste, etc.

(function() {
  var textBox = document.getElementById("text-box");
  textBox.addEventListener("input", function(e) {
    var val = this.value,
      rx = /[^\d]/g;
    if (rx.test(val)) {
      var pos = this.selectionStart;
      this.value = val.replace(rx, "");
      this.selectionStart = pos;
      this.selectionEnd = pos - 1;
    }
  });
})();