function navBtnSetup(){
	var IMG_URL = "http://mashupkorea.com/2008/images/";

	var btn_home    = document.getElementById('menu_home');
	var btn_contest	= document.getElementById('menu_contest');
	var btn_event	= document.getElementById('menu_event');
	var btn_blog	= document.getElementById('menu_blog');
	var btn_qna		= document.getElementById('menu_qna');

	var arr = new Array(btn_home,btn_contest,btn_event,btn_blog,btn_qna);

	for(var i=0,max=arr.length; i<max; i++){
		var img = arr[i];

		if(img.addEventListener){
			img.addEventListener('mouseover',IMG_URL + imageSwitching,false);
			img.addEventListener('mouseout',IMG_URL + imageSwitching,false);
		}else{
			img.attachEvent('onmouseover',IMG_URL + imageSwitching);
			img.attachEvent('onmouseout',IMG_URL + imageSwitching);
		}
	}
}

function imageSwitching(e){
	var target = (window.event)?window.event.srcElement:e.target;
	var src = target.src;

	var filename = src.substring(0,src.lastIndexOf('.'));
	filename = filename.substring(filename.lastIndexOf('/') + 1);

	if(filename.substr(filename.length - 1) == '_'){
		target.src = src.replace('_.','.');
	}else{
		target.src = src.replace(filename,filename + '_');
	}
}

function init(){
	//daumFlash('main.swf',486,509,'flash_banner');
	navBtnSetup();
}

function addLoadEvent(func)
{    
    var oldonload = window.onload;
    if (typeof window.onload != 'function')
    {
        window.onload = func;
    } 
    else 
    {
        window.onload = function()
        {
            oldonload();
            func();
        }
    }
}

// addLoadEvent(init);