var popParts = new Array();
var popPartNames = new Array();
var currentDisplayPart = 0;
var partsList;
var theList = "";
var partsListItems = new Array();

function initPopPartsSwapper() {
  popParts = document.getElementsBySelector('div.popular-part');
  partsList = document.getElementById('popular-parts-list');
  
  for( i=0; i < popParts.length; i++ ){ 
    popParts[i].style.display='none';
    popPartNames[i] = popParts[i].getElementsByTagName('h4')[0].getElementsByTagName('a')[0].innerHTML;	
  }
  
  theList += '<ul>\n'; 
  for( i=0; i< popPartNames.length; i++ ) {
    theList += '<li><a href="javascript:switchPopularPartsDisplay(' 
                            + i + ');" class="popular-part-name unselected">' + popPartNames[i] + '</a></li>';
  
  } theList += '</ul>\n';

  partsList.innerHTML = theList;

  popParts[currentDisplayPart].style.display='block';
  partsListItems = document.getElementsBySelector("a.popular-part-name")
  partsListItems[currentDisplayPart].setAttribute("class","popular-part-name selected");
}

function switchPopularPartsDisplay( n ) {
  popParts[currentDisplayPart].style.display='none';
  partsListItems[currentDisplayPart].setAttribute("class","popular-part-name unselected");
  currentDisplayPart = n;
  partsListItems[currentDisplayPart].setAttribute("class","popular-part-name selected");
  popParts[currentDisplayPart].style.display='block';
}