function show_hide(id)
{
	if(document.getElementById(id))
	{
		var visible = document.getElementById(id).style.visibility;

		if(visible == 'visible')
		{
			document.getElementById(id).style.visibility = "hidden";
		}
		else
		{
			document.getElementById(id).style.visibility = "visible";
		}
	}
	
}