Re-populating an empty multiselect...

[justincredible]

function buildSelect(status){
     var xmlhttp=false;
     try{// Firefox, Opera 8.0+, Safari
          xmlHttp=new XMLHttpRequest();
     }
     catch (e){// Internet Explorer
          try{
               xmlHttp=new ActiveXObject("Msxml2.XMLHTTP");
          }
          catch (e){
               try{
                    xmlHttp=new ActiveXObject("Microsoft.XMLHTTP");
               }
               catch (e){
                    alert('Your browser does not support AJAX!');
                    return false;
               }
          }
     }
     var file = 'chapterAjax.php?chapterStatus=';
     xmlHttp.open('GET',file+status,true);
     xmlHttp.onreadystatechange=function(){
          if(xmlHttp.readyState==4){
               for (x = document.getElementById('selectedChapter').length; x >= 0; x--) {
                    document.getElementById('selectedChapter')[x] = null;
               }
               var content = xmlHttp.responseText.split(",");
               document.getElementById('selectedChapter')[0] = content[377];
               for(var i=0;i<content.length;i++){
                    document.getElementById('selectedChapter')[i] = content[i];
               }
               document.getElementById('activeChapterBox').disabled = false;
               document.getElementById('workingChapterBox').disabled = false;
               document.getElementById('nonactiveChapterBox').disabled = false;
               document.getElementById('hiddenChapterBox').disabled = false;
               document.getElementById('modifiedChapterBox').disabled = false;
     }
     else{
          document.getElementById('activeChapterBox').disabled = true;
          document.getElementById('workingChapterBox').disabled = true;
          document.getElementById('nonactiveChapterBox').disabled = true;
          document.getElementById('hiddenChapterBox').disabled = true;
          document.getElementById('modifiedChapterBox').disabled = true;}
     }
     xmlHttp.send(null);
     return;
}

I cannot seem to get the bolded part to do the correct thing.

The for-loop before that is used to completely wipe out my multiselect and I want the bolded code to re-populate that multiselect with the elements that are now in content.

Any ideas?

[justincredible]

This is the error that I am getting in firebug which means absolutely nothing to me:

[Exception... "Failure" nsresult: "0x80004005 (NS_ERROR_FAILURE)" location: "JS frame :: http://myurl.com :: anonymous :: line 1035" data: no]

[justincredible]

When I alert on content[i] it gives me the right thing so I know it is splitting it correctly.

document.getElementById('selectedChapter')[i] is obviously wrong.

I believe I tried document.getElementById('selectedChapter').option[i] as well but it didn't work either.