[bes]

<select id="sel">
  <option>зацените картинку
  <option>5
  <option>3
  <option>1
</select>


<script>
window.onload = function () {
  var sel = document.getElementById('sel');
  sel.onchange = function () {
    var elem = this.options[this.selectedIndex];
    elem.value = elem.text;
    this.setAttribute('disabled', 'disabled');
  }
}
</script>