disable first 3 characters

by Faisal Khan Janjua

HTML

<input type="text" name="phone" id="phone" placeholder='' value='0345' maxlength='13' />

JavaScript

$(document).keydown(function (e) {
    var l = $('#phone').val().length;
    if ((e.keyCode === 8 || e.keyCode === 46) && l == 3) {
        return false;
    } else {
        return true;
    }
});
// disabling Select All and Delete/Backspace
/* $(document).keyup(function (e) {
    var l = $('#phone').val().length;
    var tempVal = $('#phone').val().substring(0, 3);
    if(l < 3){
      $('#phone').val(tempVal);
    }
}); */