function toggleMarker(obj, startHeight, endHeight) {
    
    //get siblings of this element and tween them
    var siblings = $(obj).siblings();
    for(var i=0; i < siblings.length; i++) {
            if(siblings[i].getHeight() > (startHeight +3))
                new Effect.Tween(siblings[i], endHeight, startHeight, {duration:1.0}, function(r){ this.style.height = r+"px"});
    }

    //tween height for this element
    new Effect.Tween(obj, startHeight, endHeight, {duration:1.0}, function(p){ this.style.height = p+"px"});
} 
var slideLock = false;

function slideMenu(obj) {

    if(!slideLock) {
        slideLock = true;
        if(obj.getHeight() > 30)
            new Effect.Scale(obj, 8.333, {scaleY:true, scaleX:false, scaleContent:false, afterFinish:function(){slideLock = false;}});
        else
            new Effect.Scale(obj, 1200, {scaleY:true, scaleX:false, scaleContent:false, afterFinish:function(){slideLock = false;}});
    }
}

function twitter_share() {

      var imgSourceTmp = document.getElementById('lightboxImage').src;
			var imgSource = imgSourceTmp.substring(imgSourceTmp.indexOf('.com/') + 4)
      var twitter_url = 'http://twitter.com/share';
      var url = 'http://www.entropiauniverse.com/media/images/?shareImg='+imgSource;//'http://www.entropiauniverse.com/get-img.html?img='+imgSource;
      var text = 'Check out this cool Entropia Universe screenshot!';
				
      window.open(encodeURI(twitter_url+'?url='+url+'&text='+text),'twitter_tweet','width=550,height=370');
}

var backisScrolling = false;
var isShaking = false;

function scrollBackground() {
      //hide star
      $('star').hide();
      //change background image
      document.body.setStyle({'backgroundImage': 'url(/layout-images/background_space.jpg)'});
      //change background-position
      document.body.setStyle({'backgroundPosition': '50% -250px'});
      
      backisScrolling = true;
      new Effect.Tween(null, 0, 250, {duration:7.0}, function(p){shakeAndScroll(p);});
}

function shakeAndScroll(value) {
    var rand = Math.random()*20;
   document.body.setStyle({'marginTop': (value*1.5)+'px'});
   document.body.setStyle({'backgroundPosition': 50+rand+'% '+((value) -250)+'px'});
   $('page-container').setStyle({'paddingLeft':rand+'px'});
   if(value > 190)
        backisScrolling = false;

   if(!isShaking && backisScrolling) {
        isShaking = true; 
        doShake();
   }      
}