title: enable or disable option from select
body: <p>I am trying to make an option either selectable OR non-selectable based on whether or not they chose another option. For example, if there is options 1-6 and they have NOT chosen option 1 in their first select box, then in that SAME select box and any other in the form, then option 6 could NOT be chosen. </p>
  
  <p>I looked around, but everything is about clicking a button to achieve this.</p>
  
  <p>This is the code I have (I have also tried onclick)</p>
  
  <pre><code>   &lt;script type="text/javascript"&gt;
        function makeDisable(){
        var x=document.getElementById("mySelect2");
        x.disabled=true
        }
       function makeEnable(){
           var x=document.getElementById("mySelect2");
            x.disabled=false
       }&lt;/script&gt;
       &lt;form&gt;
          &lt;select class="mySelect" id="mySelect"&gt;
          &lt;option onchange="makeEnable()" value="Enable list"&gt;Apple&lt;/option&gt;
          &lt;option onchange="makeDisable()" value="Disable list"&gt;Banana&lt;/option&gt;
          &lt;option id="mySelect2" disabled="true"&gt;Orange&lt;/option&gt;
      &lt;/select&gt;
      &lt;/form&gt;
  </code></pre>