var springads = new Object();
var today = new Date(); 
var zero_date = new Date(0,0,0); 
today.setTime(today.getTime() - zero_date.getTime()); 
var cookie_expire_date = new Date(today.getTime() + (8 * 7 * 86400000)); 
springads['odd'] = new Array();
springads['even'] = new Array();

function changeSpringAd() {
	var c = getCookie('springad');
	for(var i=0; i< springads['even'].length;i++) {
		if(springads['even'][i]) {
			springads['even'][i].style.display = (c=='even') ? 'block':"none";
			springads['even'][i].style.visibility = (c=='even') ? 'visible':'hidden';
		}
	}
	for(var i=0; i< springads['odd'].length;i++) {
		if(springads['odd'][i]) {
			springads['odd'][i].style.display = (c=='odd') ? 'block':"none";
			springads['odd'][i].style.visibility = (c=='odd') ? 'visible':'hidden';
		}
	}
}

function initspringad() {
	var divs = document.getElementsByTagName('DIV');
	var d='even';
	var a=0;
	for(var i=0; i< divs.length;i++){
		if(divs[i].className=='springad'){
			d = (d=='even')?'odd':'even';
			if( typeof divs[i] != 'undefined' ) springads[d][a] = divs[i];
			a++;
 		}
	}
	var c = getCookie('springad');
	//alert(c);

	if(c=='odd'){ 
		setCookie('springad','even',cookie_expire_date,'/',false,false);
	} else {
		setCookie('springad','odd',cookie_expire_date,'/',false,false);
	}
	changeSpringAd();
}

function getCookie (name) {
    var dc = document.cookie;
    var cname = name + "=";
    if (dc.length > 0) {
      begin = dc.indexOf(cname);
      if (begin != -1) {
        begin += cname.length;
        end = dc.indexOf("", begin);
        if (end == -1) end = dc.length;
        cs = (dc.substring(begin, end)=='even' || dc.substring(begin, end)=='odd') ? dc.substring(begin, end):'even';
        return unescape(cs);
        }
      }
    return 'even';
}

function setCookie(name,value,expires,path,domain,secure) { 
	var cookieString = name + "=" +escape(value) + 
		( (expires) ? ";expires=" + expires.toGMTString() : ";expires="+cookie_expire_date.toGMTString()) + 
		( (path) ? ";path=" + path : ";path=/") + 
		( (domain) ? ";domain=" + domain : ";domain="+ window.location.toString().split("//")[1].split("/")[0] ) + 
		( (secure) ? ";secure" : ""); 
	document.cookie = cookieString; 
	//alert(cookieString);
}

window.onload = initspringad;