function my_changenav(my_div,my_tt,my_cnt,my_cssa,my_cssb,my_is) {  //div，导航按钮，内容，选中的css，不选的css，是否记忆1=记忆
	var Tags=document.getElementById(my_div).getElementsByTagName(my_tt); 
	var TagsCnt=document.getElementById(my_div).getElementsByTagName(my_cnt); 
	var len=Tags.length; 
	var flag
	if (my_is==1){
		flag=my_getcookie("leoexmenu");
	} else {
		flag=0
	}
	for(i=0;i<len;i++){
		Tags[i].value = i;
		Tags[i].onmouseover=function(){changenav(this.value,my_is)}; 
		TagsCnt[i].className='undis'; 
	}
	Tags[flag].className=my_cssa;
	TagsCnt[flag].className='dis'; 

	function changenav(v,my_is){ 
		Tags[flag].className=my_cssb;
		TagsCnt[flag].className='undis';
		flag=v; 
		Tags[v].className=my_cssa;
		TagsCnt[v].className='dis';
		if (my_is==1){
			document.cookie = 'leoexmenu='+v;
		}
	}

	function my_getcookie(cookieName) {
		var cookieString = document.cookie;
		var start = cookieString.indexOf(cookieName + '=');
		if (start == -1)
		return 0;
		start += cookieName.length + 1;
		var end = cookieString.indexOf(';', start);
		if (end == -1) return unescape(cookieString.substring(start));
		return unescape(cookieString.substring(start, end));
	}

}