function $d(id){return document.getElementById(id)}
function goto(tag,sname,num){
	var t1 = $d("t_1");
	var c1 = $d("box_1");

	var t2 = $d("t_2");
	var c2 = $d("box_2");

	if(num==1){
		t1.className = "up";
		t2.className = "";
		c1.style.display = "block";
		c2.style.display = "none";
	}
	else if(num==2){
		t2.className = "up";
		t1.className = "";
		c2.style.display = "block";
		c1.style.display = "none";
	}
}