//change class
function setElementClassById(elem, value) {
	if(elem == 'size120'){
		var selectElment = "size120";
		var hideElment1 = "size125";
		var hideElment2 = "size234";
		
		var selectButton = "stock120";
		var normalButton1 = "stock125";
		var normalButton2 = "stock234";
		
	}else if(elem == 'size125'){
		var selectElment = "size125";
		var hideElment1 = "size120";
		var hideElment2 = "size234";
		
		var selectButton = "stock125";
		var normalButton1 = "stock120";
		var normalButton2 = "stock234";
	}else{
		var selectElment = "size234";
		var hideElment1 = "size120";
		var hideElment2 = "size125";
		
		var selectButton = "stock234";
		var normalButton1 = "stock120";
		var normalButton2 = "stock125";
	}
	
	
	if(document.getElementById) {
		var selectObj = document.getElementById(selectElment);
		var selectBtn = document.getElementById(selectButton);
			if(selectObj) {
			selectObj.className = 'selected';
			selectBtn.className = 'selected';
		}
		var hideObj1 = document.getElementById(hideElment1);
		var normalBtn1 = document.getElementById(normalButton1);
		hideObj1.className = 'hidden';
		normalBtn1.className = 'normal';
		
		var hideObj2 = document.getElementById(hideElment2);
		var normalBtn2 = document.getElementById(normalButton2);
		hideObj2.className = 'hidden';
		normalBtn2.className = 'normal';
	}
}

function setExp(){
	var setObj = document.getElementById('bannerExplanation');
	setObj.className = 'normal';
}

function hideExp(){
	var setObj = document.getElementById('bannerExplanation');
	setObj.className = 'hidden';
}