function tabshow(id){
	if (id==1){
		document.getElementById("task1").className="task";
		document.getElementById("dy_1").style.display="block";
		document.getElementById("dy_2").style.display="none";
		document.getElementById("dy_3").style.display="none";
		document.getElementById("task2").className="";
		document.getElementById("task3").className="";
	}
	if (id==2){
		document.getElementById("task2").className="task";
		document.getElementById("dy_1").style.display="none";
		document.getElementById("dy_2").style.display="block";
		document.getElementById("dy_3").style.display="none";
		document.getElementById("task1").className="task2";
		document.getElementById("task3").className="";
	}
	if (id==3){
		document.getElementById("task3").className="task";
		document.getElementById("dy_1").style.display="none";
		document.getElementById("dy_2").style.display="none";
		document.getElementById("dy_3").style.display="block";
		document.getElementById("task1").className="task2";
		document.getElementById("task2").className="";
	}
 }