if (document.images)
    {
      preload_image_object = new Image();
      // set image url
      image_url = new Array();
      image_url[0] = "../images/menu_home_hover_ar.png";
      image_url[1] = "../images/menu_about_hover_ar.png";
	  image_url[2] = "../images/menu_individual_hover_ar.png";
	  image_url[3] = "../images/menu_institutional_hover_ar.png";
	  image_url[4] = "../images/menu_research_hover_ar.png";

       var i = 0;
       for(i=0; i<=4; i++) 
         preload_image_object.src = image_url[i];
    }

    
  


var menu=function(){
	var t=15,z=50,s=6,a;
	function dd(n){this.n=n; this.h=[]; this.c=[]}
	dd.prototype.init=function(p,c){
		a=c; var w=document.getElementById(p), s=w.getElementsByTagName('ul'), l=s.length, i=0;
		for(i;i<l;i++){
			var h=s[i].parentNode; this.h[i]=h; this.c[i]=s[i];
			h.onmouseover=new Function(this.n+'.st('+i+',true)');
			h.onmouseout=new Function(this.n+'.st('+i+')');
		}
	}
	dd.prototype.st=function(x,f){
		var c=this.c[x], h=this.h[x], p=h.getElementsByTagName('a')[0];
		clearInterval(c.t); c.style.overflow='hidden';
		if(f){
			p.className+=' '+a;
			if(!c.mh){c.style.display='block'; c.style.height=''; c.mh=c.offsetHeight; c.style.height=0}
			if(c.mh==c.offsetHeight){c.style.overflow='visible'}
			else{c.style.zIndex=z; z++; c.t=setInterval(function(){sl(c,1)},t)}
		}else{p.className=p.className.replace(a,''); c.t=setInterval(function(){sl(c,-1)},t)}
	}
	function sl(c,f){
		var h=c.offsetHeight;
		if((h<=0&&f!=1)||(h>=c.mh&&f==1)){
			if(f==1){c.style.filter=''; c.style.opacity=1; c.style.overflow='visible'}
			clearInterval(c.t); return
		}
		var d=(f==1)?Math.ceil((c.mh-h)/s):Math.ceil(h/s), o=h/c.mh;
		c.style.opacity=o; c.style.filter='alpha(opacity='+(o*100)+')';
		c.style.height=h+(d*f)+'px'
	}
	return{dd:dd}
}();