function random_img() {
	var img_list = new Array();
	img_list[0] = "./img/header/index01.jpg";
	img_list[1] = "./img/header/index02.jpg";
	img_list[2] = "./img/header/index03.jpg";
	img_list[3] = "./img/header/index04.jpg";
	img_list[4] = "./img/header/index05.jpg";

	var img_no = Math.floor(img_list.length * Math.random());
	var img_obj = document.getElementById('random_img');


	img_obj.src = img_list[Math.floor(img_no)];
	
}

function setFader(targetObj,targetAlpha) {
	targetObj.targetAlpha = targetAlpha;
	if(targetObj.currentAlpha==undefined)
	{
		targetObj.currentAlpha = 100;
	}
	if(targetObj.currentAlpha==targetObj.targetAlpha)
	{
		return;
	}
	if(!targetObj.fading)
	{
		if(!targetObj.fader)
		{
			targetObj.fader = fader;
		}

		targetObj.fading = true;
		targetObj.fader();
	}
}

function fader() {
	this.currentAlpha += (this.targetAlpha - this.currentAlpha) * 0.1;
	if(Math.abs(this.currentAlpha-this.targetAlpha)<1)
	{
		this.currentAlpha = this.targetAlpha;
		this.fading = false;
	}

	var alpha = parseInt(this.currentAlpha);
	this.style.opacity = alpha/100;
	this.style.filter = 'alpha(opacity='+alpha+')';
	if(this.fading)
	{
		var scope = this;
		setTimeout(function(){fader.apply(scope)}, 80);
	}
}


function boot_function() {
	random_img();
}

function addEvent(eventTarget, eventName, func) {
	if(eventTarget.addEventListener) {
		eventTarget.addEventListener(eventName, func, false);
	}else if(window.attachEvent) {
		eventTarget.attachEvent('on' + eventName, function(){func.apply(eventTarget);});
	}
}

addEvent(window, 'load', boot_function);