function qiehuan(num)
{
	for(var id = 0;id<=5;id++)
	{
		if(id==num)
		{
			document.getElementById("qh_con"+id).style.display="block";
			document.getElementById("mynav"+id).className="nav_on";
		}
		else
		{
			document.getElementById("qh_con"+id).style.display="none";
			document.getElementById("mynav"+id).className="";
		}
	}
}