function setCaretPosition(ctrl, pos) {
  // Modern browsers
  if (ctrl.setSelectionRange) {
    ctrl.focus();
    ctrl.setSelectionRange(pos, pos);
  
  // IE8 and below
  } else if (ctrl.createTextRange) {
    var range = ctrl.createTextRange();
    range.collapse(true);
    range.moveEnd('character', pos);
    range.moveStart('character', pos);
    range.select();
  }
}

// Set the cursor position of the "#test-input" element to the end when the page loads
var input = document.getElementById('test-input');
setCaretPosition(input, input.value.length);