function addLoadEvent(func) {

  var oldonload = window.onload;
  if (typeof window.onload != 'function') {
    
    window.onload = func;
  } else {
      
    window.onload = function() {
      oldonload();
      func();
    } 
  } 
}

function startSlideshow() {
  
  initSlideShow($('mySlideshow'), mySlideData);
}

addLoadEvent(startSlideshow);