function show_div (target){
	var span_array=document.getElementsByTagName("span");
	
	for (var index=0; index<span_array.length; index++)
	
	{span_array[index].style.display="none";}
		 
	
	
	var target=document.getElementById(target);
	
	target.style.display="block";
}

function hide_div (target){
	var target=document.getElementById(target);
	target.style.display="none";
}