function set_iframe_url(jpUrl){
 document.getElementById('productIframe').src='vol' + jpUrl + '.html';
	setClass(jpUrl);
}

function setClass(clickId) {
	if( clickId == 1 ) {
		document.getElementById('vol1Btn').className = "nowActive";
	}
	else {
		document.getElementById('vol1Btn').className = "";
	}
	if( clickId == 2 ) {
		document.getElementById('vol2Btn').className = "nowActive";
	}
	else {
		document.getElementById('vol2Btn').className = "";
	}
	if( clickId == 3 ) {
		document.getElementById('vol3Btn').className = "nowActive";
	}
	else {
		document.getElementById('vol3Btn').className = "";
	}
}