function preloadImage(imgSrc) 
{
  if (document.preloadArray == null) 
    document.preloadArray = new Array;

  var i = document.preloadArray.length;

  document.preloadArray[i]     = new Image;
  document.preloadArray[i].src = imgSrc;
}

function preloadImages(UserType) 
{
  preloadImage('../images/side_homeX.gif');
  preloadImage('../images/side_mainX.gif');
  preloadImage('../images/side_loginX.gif');
  preloadImage('../images/side_logoutX.gif');
  preloadImage('../images/side_reloginX.gif');
  preloadImage('../images/side_log_service_callX.gif');

  if (UserType == 2) { // CLIENT
    preloadImage('../images/side_logServiceCallX.gif');        
    preloadImage('../images/side_jobListX.gif');  
    preloadImage('../images/side_consumablesOrderX.gif');
    preloadImage('../images/side_reportsX.gif');
  } else if (UserType == 1) { // TECH
    preloadImage('../images/side_logServiceCallX.gif');
    preloadImage('../images/side_jobListX.gif');
    preloadImage('../images/side_jobDetailsX.gif');
    preloadImage('../images/side_reportsX.gif');
  } else if (UserType == 0) { // OFFICE
    preloadImage('../images/side_maintenanceX.gif');
    preloadImage('../images/side_statisticsX.gif');
    preloadImage('../images/side_cacheFilesX.gif');
    preloadImage('../images/side_viewErrorLogX.gif');
  }
}

                        
function swapImage(imgObj, imgSrc)
{
  if (document.swapArray != null) {
    restoreImage();
  }

  var obj = eval(imgObj);
  var swapArray = new Array;

  if (obj != null) {
    swapArray[0] = obj;
    swapArray[1] = obj.src;
    obj.src = imgSrc;
  } else {
    alert("DOH!");
  }
  
  document.swapArray = swapArray;
}


function restoreImage()
{
  if (document.swapArray != null) {
    document.swapArray[0].src = document.swapArray[1];
    document.swapArray = null;
  }
}