var MenuOpen="";
var MyTime=0;
var Interval1;
var time_in;
var time_out;
function resettimer() {
	MyTime=0;
	if (Interval1!=undefined) clearInterval(Interval1);
}
function timecontrol(){
	MyTime++;
	if (MyTime==5) {
		MyTime=0;
		swap("");
		clearInterval(Interval1);
	}
}
function timetoexp(){
	Interval1=setInterval("timecontrol()",1000);	
}
function swap(obj){
	resettimer();
	
	
	// nessun menù selezionato
	if (obj=="" && MenuOpen!="") {
		
		// chiude un menù
		
		opacity(MenuOpen, 100, 0, 500);
		
	}
	// menu selezionato (inizio)
	if (obj!="" && MenuOpen=="") {
    
		opacity(obj, 0, 100, 500);
		
	}
	if (obj!="" && MenuOpen!="" && obj!=MenuOpen) {
		//document.getElementById(MenuOpen).style.display="none";
		//document.getElementById(obj).style.display="block";
		
		opacity(MenuOpen, 100, 0, 500);
		
		opacity(obj, 0, 100, 500);
	}
	MenuOpen=obj;
}
function opacity(id, opacStart, opacEnd, millisec) { 
    //speed for each frame 
    var speed = 1; //Math.round(millisec / 1000); 
  
    var timer = 0; 

    //determine the direction for the blending, if start and end are the same nothing happens 
    if(opacStart > opacEnd) { 
        
        for(i = opacStart; i >= opacEnd; i--) { 
            time_out=setTimeout("changeOpac(" + i + ",'" + id + "')",(timer * speed)); 
            
            timer++;
            
            
        } 
        
        //Interval2=setInterval("changeOpac(" + i + ",'" + id + "',-1)",50);
        
    } else if(opacStart < opacEnd) { 
        
        
        for(i = opacStart; i <= opacEnd; i++) 
        { 
            time_in=setTimeout("changeOpac(" + i + ",'" + id + "')",(timer * speed)); 
            timer++;
            
             
        } 
        
       
        //Interval2=setInterval("changeOpac(" + i + ",'" + id + "',1)",50);        
    } 
   
} 
//change the opacity for different browsers 
function changeOpac(opacity, id) { 
    var object = document.getElementById(id).style; 
    object.opacity = (opacity / 100); 
    object.MozOpacity = (opacity / 100); 
    object.KhtmlOpacity = (opacity / 100); 
    object.filter = "alpha(opacity=" + opacity + ")"; 
    if (opacity==0) object.display='none';
    else if (opacity==100) object.display='block';
}