var timer = null;
var offset = 5000;
var index = 0;
var target = ["01","02","03","04","05","06"];

//大图交替轮换
function slideImage(i){
    var id = 'image_'+ target[i];
    $('#'+ id).animate({opacity: 1}, 800).show().siblings(':visible').animate({opacity: 0}, 800).hide();
}
//图片标题内容交替轮换
function slideText(i){
    var id = 'word_'+ target[i];
    $('#'+ id).animate({opacity: 1}, 'slow').show().siblings().hide();
}

//bind thumb a
function hookThumb(){    
    $('#thumbs li a')
        .bind('click', function(){
            if (timer) {
                clearTimeout(timer);
            }                
            var id = this.id;            
            index = getIndex(id.substr(6));
            rechange(index);
            slideImage(index); 
            slideText(index);
            timer = window.setTimeout(auto, offset);  
            this.blur();            
            return false;
        });
}
//bind next/prev img
function hookBtn(){
    $('#thumbs li img').filter('#play_prev,#play_next')
        .bind('click', function(){
            if (timer){
                clearTimeout(timer);
            }
            var id = this.id;
            if (id == 'play_prev') {
                index--;
                if (index < 0) index = 6;
            }else{
                index++;
                if (index > 6) index = 0;
            }
            rechange(index);
            slideImage(index);
            slideText(index);
            timer = window.setTimeout(auto, offset);
        });
}
//get index
function getIndex(v){
    for(var i=0; i < target.length; i++){
        if (target[i] == v) return i;
    }
}
function rechange(loop){
    var id = 'thumb_'+ target[loop];
    $('#thumbs li a.current').removeClass('current');
    $('#'+ id).addClass('current');
}
function auto(){
    index++;
    if (index > 5){
        index = 0;
    }
    rechange(index);
    slideImage(index);
    slideText(index);
    timer = window.setTimeout(auto, offset);
}
$(function(){    
    //change opacity
    $('div.word').css({opacity: 0.85});
    auto();  
    hookThumb(); 
    hookBtn();
    
});