Carousel Figure project summary

window.onload=function () {
 
    var items = document.getElementsByClassName ( " Item " );                       case obtained images, a collating
     var alist = document.getElementById ( " alist " ) .getElementsByTagName ( " A " ); dots obtained at this time, a button to switch picture 
    var lbtn = document.getElementById ( " lbtn " ); to obtain the left button
     var RBTN = document.getElementById ( " RBTN " ); to obtain the right button

    var index = 0 ; index declare a variable, as an index, the default is 0

    var clearactive=function () {
        for (var m=0;m<items.length;m++){
            items [m] .className = " Item " ; this case the modified class values for all images "item", full restoration of the original pattern
        }
        for (var m=0;m<alist.length;m++){
           alist [m] .className = " Ali " At this time, all of the dots is to modify the value of class "ali", to restore the original pattern

     }};

goindex function = var () {                   
    clearactive (); 
    items [index] = .className "Active Item"; call the above clearactive () function, and while the class value and the dot image increases and activea avtive                                           

    alist [index] = .className "Ali activea"             
};                                                   

var gonext = function () {gonext declare a method, and determines the value of the index, then the index value of between 4 and locked in 0, if the index is equal to 5, 
    if (index <4) {the index = 0, and jump to the first image at this time 0. 
        ++ index; 
    } the else { 
        index = 0 
    } 
    goindex () 
}; 

var Goup = function () { 
    IF (index == 0) {index determination, if the index = 0, then execute index = 4, if the index is not equal to 0, the index continues to decrement 
        index =. 4;                                      
    } the else { 
        index the 
    } 
    goindex () 
};


rbtn.onclick = function () {right button to execute gonext () method 
    gonext (); 

}; 

lbtn.onclick = function () {Goup left button to execute () method 
    Goup () 
}; 


the setInterval (function () {this was added at a timer, set to two parameters, the first parameter is anonymous function, the second time, and calls gonext () method, performed once every 6 seconds 
    gonext () 
}, 6000);