/***********************************************************************

1 add event

***********************************************************************/


if(window.addEventListener) {
	window.addEventListener("load",rollOverImg,false);
}else if(window.attachEvent) {//for ie
	window.attachEvent("onload",rollOverImg);
}


/***********************************************************************

2 rollOver function

***********************************************************************/


function rollOverImg() {
	
	var conf = {
		className : 'img-over',
		postfix : '-on'
	};
	
	var imgNodeList = getElementsByClassName(conf.className);
	var node;
	
	for( var i=0, len=imgNodeList.length; i<len; i++ ) {
		node = imgNodeList[i];
		node.originalSrc = node.src;
		node.rolloverSrc = node.originalSrc.replace( /(\.gif|\.jpg|\.png)/,conf.postfix+"$1" );
		
		preloadImage( node.rolloverSrc );
		
		node.onmouseover = function() {
			this.src = this.rolloverSrc;
		}
		node.onmouseout = function() {
			this.src = this.originalSrc;
		}
	}
	
	//set other option
	externalLinkOpen();
}

function getElementsByClassName( name ) {
	var elements = [];
	var allElements = document.getElementsByTagName('*');
	for( var i=0, len=allElements.length; i<len; i++ ) {
		
		var cName = allElements[i].className;
		var hit = cName.indexOf(name);
			
		if( hit != -1 ) {
			elements.push( allElements[i] );
		}
	}
	return elements;
}

preloadImages = [];

function preloadImage( url ) {
	var p = preloadImages;
	var l = p.length;
	p[l] = new Image();
	p[l].src = url;
}


/***********************************************************************

3 externalLink function

***********************************************************************/


function externalLinkOpen(){
	var Anchor = document.getElementsByTagName('a');
	for( var i=0; i<Anchor.length; i++ ){
		var address = Anchor[i];
		
		if( address.className == 'external' ){
			address.onclick = function(){
				window.open(this.getAttribute('href'),'_blank');
				return false; 
			}
		}
	}
	var Anchor02 = document.getElementsByTagName('area');
	for( var i=0; i<Anchor02.length; i++ ){
		var address = Anchor02[i];
		
		if( address.className == 'external' ){
			address.onclick = function(){
				window.open(this.getAttribute('href'),'_blank');
				return false; 
			}
		}
	}
}