Disable textbox when ListIndex = 2

I have 2 Select Boxes...
I put an OnChange event on the First Select box....

If the first listbox' ListIndex = 2...I'd like the second two be disabled...

If the ListIndex changes again...I want to enable the second listbox...

The below code does the disabling....but does not check for listindex..help is appreciated

Code:

---

function disablen(veld){
  with (document.myForm.elements[veld]) {
    disabled = !disabled;
  }
}

---

Code:

---

<script language="javascript">
function Lists(){
alert(form1.select.selectedIndex);
if(form1.select.selectedIndex==2){
        form1.select2.disabled = 1;
        form1.select3.disabled = 1;
} else {
        form1.select2.disabled = 0;
        form1.select3.disabled = 0;
}
}
</script>
<form name="form1" method="post" action="">
  <select name="select" onChange="Lists();">
    <option selected>test</option>
    <option>disable</option>
    <option>test3</option>
  </select>
  <select name="select2">
    <option selected>test</option>
    <option>test2</option>
    <option>test3</option>
    <option>test4</option>
    <option>test5</option>
  </select>
  <select name="select3">
    <option selected>test</option>
    <option>test2</option>
    <option>test3</option>
    <option>test4</option>
  </select>
</form>

---

Don't forget the index starts at 0

:)

did this work satisfactorily for you