function play(id){
	var i = 0;
	
	for(i=0;i<=10;i++){
		document.getElementById('play_'+i).style.visibility = "hidden";
		document.getElementById('play_'+i).style.display = "none";
	}
	
	document.getElementById('play_'+id).style.visibility = "visible";
	document.getElementById('play_'+id).style.display = "block";
}