var n=0;
function Mea(value){
 n=value;
 setBg(value);
 plays(value);
 }
function setBg(value){
 for(var i=0;i<4;i++){
 if(value==i){
 document.getElementById("a"+value).className='act';
 } else{
 document.getElementById("a"+i).className='nor';
 }
 }
}
function plays(value){
 for(i=0;i<4;i++){
 if(i==value){
 document.getElementById("pc_"+value).style.display="block";
 }else{
 document.getElementById("pc_"+i).style.display="none";
 }
}
}
function clearAuto(){clearInterval(autoStart)}
function setAuto(){autoStart=setInterval("auto(n)", 3500)}
function auto(){
 n++;
 if(n>3)n=0;
 Mea(n);
}
function sub(){
 n--;
 if(n<0)n=3;
 Mea(n);
}
setAuto();