function acceptNum(evt)
{    // NOTE: Backspace = 8, Enter = 13, '0' = 48, '9' = 57
     var key = nav4 ? evt.which : evt.keyCode;
     return (key <= 13 || (key >= 65 && key <= 90 || key >= 97 && key <=122 || key==32 || key==45 || key >= 48 && key <= 57));
}