function fa(i)
{
 switch(i)
 {
 case 1:
document.getElementById("fa1").style.display="block";
document.getElementById("fa2").style.display="none";
break;
 case 2:
document.getElementById("fa1").style.display="none";
document.getElementById("fa2").style.display="block";
break;
 }
}



function y(i)
{
 switch(i)
 {
 case 1:
document.getElementById("y1").style.display="block";
document.getElementById("y2").style.display="none";
document.getElementById("y3").style.display="none";
document.getElementById("y4").style.display="none";
break;
 case 2:
document.getElementById("y1").style.display="none";
document.getElementById("y2").style.display="block";
document.getElementById("y3").style.display="none";
document.getElementById("y4").style.display="none";
break;
 case 3:
document.getElementById("y1").style.display="none";
document.getElementById("y2").style.display="none";
document.getElementById("y3").style.display="block";
document.getElementById("y4").style.display="none";
break;
 case 4:
document.getElementById("y1").style.display="none";
document.getElementById("y2").style.display="none";
document.getElementById("y3").style.display="none";
document.getElementById("y4").style.display="block";
break;
 }
}