title: jQuery disable dropdownlist item by text
body: <p>I have a asp:net dropdownlist which has extra items appended server side:</p>
  
  <pre><code>&lt;asp:DropDownList ID="ddlResult" runat="server"&gt;
      &lt;asp:ListItem Value="" Text="-- Please Select --"&gt;&lt;/asp:ListItem&gt;
  &lt;/asp:DropDownList&gt;
  </code></pre>
  
  <p>...and basically I would like to disable/enable an entry by the display text in jQuery. I've tried the numerous examples on here but none of them seem to work for me. eg.</p>
  
  <pre><code>$("#ddlResult option[text='Positive']").attr('disabled','disabled');
  </code></pre>
  
  <p>..or...</p>
  
  <pre><code>$("#ddlResult option[text='Positive']").hide();
  </code></pre>
  
  <p>...or ...</p>
  
  <pre><code>$("#&lt;% =ddlResult.ClientID %&gt; &gt; option[text='Positive']").attr("disabled", "disabled")
  </code></pre>
  
  <p>...amongst others.</p>
  
  <p>Can anyone advise where I am going wrong?</p>
  
  <p>Thanks in advance.</p>