function showtab(tabname, seq) {
	for (i=1 ; i<=6 ; i++) {
		if (document.getElementById(tabname + "_" +i) != null )
		{
			if (i == seq) {
			document.getElementById(tabname + "_" + i).className = "now"
			document.getElementById(tabname + "_" + i + "_content").style.display = "block"
			}
			else
			{
			document.getElementById(tabname + "_" + i).className = "normal"
			document.getElementById(tabname + "_" + i + "_content").style.display = "none"
			}
		}
	}
}