我的还没实现

function switchSlider(n){

var main = g('main_'+ n);

var ctrl = g('ctrl_'+ n);

var clear_main = g('.main-i');

var clear_ctrl = g('.ctrl-i');

for(i = 0; i < clear_ctrl.length; i++){

clear_main[i].className = clear_main[i].className.replace('main-i_active','');

clear_ctrl[i].className = clear_ctrl[i].className.replace('ctrl-i_active','');

}

mian.className = 'main-i_active';

ctrl.className = 'ctrl-i_active';

setTimeout(function(){

g('main_background').innerHTML = main.innerHTML;

})

}

这段代码不起作用