function switchTab(n){
	if(n<0||n>8){alert('超出菜单范围');return;}
	//ie ff childNodes不一样,这里不用
	var tabs = $ClassName('nav','NavSch')[0].getElementsByTagName('ul'); //偶数大菜单，奇数子菜单
	for(i=0;i<tabs.length;i++){
		if(i%2 == 0){
			tabs[i].className = 'select';
		}else{
			tabs[i].className = 'sub';
		}
	}
	
	tabs[2*n].className = 'current';
	tabs[2*n+1].className = 'sub_active';
}

//根据classname获取元素
function $ClassName(className, parentElement) {  
    var el = [], 
    _el = (document.getElementById(parentElement) || document.body).getElementsByTagName('*'); 
    for (var i=0; i<_el.length; i++ ) { 
       if (_el[i].className == className ) { 
           el[el.length] = _el[i]; 
        } 
   } 
   return el; 
} 
function navSearch()
{
	var key = document.getElementById('txtKey').value;
	if(key == ''||key=='搜索')
	{
		alert('请输入搜索关键字');
		document.getElementById('txtKey').focus();
		return;
	}
	window.location.href = '/plus/Search.asp?ChannelID=1&keyword='+escape(key);
}