var contentsNum = 0;

function setContentsChange() {
	var divs = document.getElementsByTagName("div");
	for (var i=0; i<divs.length; i++) {
		var div = divs[i];
		if (div.getAttribute("id") && div.getAttribute("id").match(/^contents\d/)) contentsNum++;
	};

	if(location.href.indexOf("#") != -1){
		var parm = location.href.substring(location.href.indexOf("#")+1);
		if(parm.match("contents")) contentsChange(parm.substring(8));
	}
};

function contentsChange(n){
	for(i=1;i<=contentsNum;i++){
		i==n ? document.getElementById("contents"+i).style.display = "block":document.getElementById("contents"+i).style.display = "none";
	};
};


if(window.addEventListener) {
	window.addEventListener("load", setContentsChange, false);
}
else if(window.attachEvent) {
	window.attachEvent("onload", setContentsChange);
}