Question

function superman(){ //some code
var opitem = $("#opinionitem").html();
opitem.replace(":opinionid","valid string");
//more code
}

gives Uncaught TypeError: Cannot call method ‘replace’ of null

alert(opitem) 

gives a string alert, not null

opinionitem

<div id="opinionitem" opinionid="0" >
        <table>
          <tr>
            <td>Image Here<img src="" onclick=""></img></td>
            <td>
              <input type="hidden" value="0"/>
              <span id="opinionid">:opinionid</span>
              <span id="opinion">:opinion</span><br/>
              <span id="note">:note</span></br>
              <span id="dateposted">:dateposted</span> - 
              <span id="lastvote">:lastvote</span> - 
              <span id=""lastcomment>:lastcomment</span>

              <button id="deleteopinionbutton" 
                      onclick="deleteopinion(:opinionid)">Delete Opinion</button>
            </td>
          </tr>
        </table>
      </div>

Answer 1

opitem=opitem.replace(":opinionid","valid string");

solved my problem, thanks thiefmaster