var lessonSelected = 1;
var lessonTimer;

function runOnLoad(f) {
   if (runOnLoad.loaded) f();
   else runOnLoad.funcs.push(f);
}

runOnLoad.funcs = [cycleThroughLessons];
runOnLoad.loaded = false;

runOnLoad.run = function() {
   if (runOnLoad.loaded) return;
   
   for (var count = 0; count < runOnLoad.funcs.length; count++) {
      try { runOnLoad.funcs[count](); }
      catch(e) { }
   }
   
   runOnLoad.loaded = true;
   delete runOnLoad.funcs;
   delete runOnLoad.run;
};

if (window.addEventListener) window.addEventListener("load", runOnLoad.run, false);
else if (window.attachEvent) window.attachEvent("onload", runOnLoad.run);
else window.onload = runOnLoad.run;

function cycleThroughLessons(){
   lessonTimer = setInterval("cycle()",5000);
}

function cycle(){
   lessonSelected = lessonSelected + 1;
   if (lessonSelected == 6){
      lessonSelected = 1;
   }
   switcher(lessonSelected);
}

function switchImageAndMore(element, lessonNum)
{
   clearInterval(lessonTimer);
   switcher(lessonNum);           
}

function switcher(lessonNum){
   var picName;
   var tempElement;
   var tempElementName;
   var i;
  
   for (i=1;i<=5;i++){
      if (lessonNum != i){
         tempElementName = 'lesson' + i;
         tempElement=document.getElementById(tempElementName);
         picName = '../Images/Lessons/' + i + '.png';
         tempElement.src = picName;
        
         tempElementName = 'lesson' + i + 'detail';
         tempElement=document.getElementById(tempElementName);
         tempElement.style.display = 'none';         
      }
   }

   tempElementName = 'lesson' + lessonNum + 'detail';
   tempElement=document.getElementById(tempElementName);
   tempElement.style.display = 'inline'; 

   tempElementName = 'lesson' + lessonNum;
   tempElement=document.getElementById(tempElementName);
   picName = '../Images/Lessons/' + lessonNum + '_Highlight.png';
   tempElement.src = picName;   
}