<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title></title>
    <script>
    var n = 1;
    function changePic(m){
        return n = m;
    }
    function change(){
        var myImg = document.getElementsByTagName("img")[0];
        myImg.src = "images/0" + n + ".jpg";
        if(n<5)nPP;
        else n=1;
    }
    
    </script>
</head>
<body onload="setInterval(change,2000);">
    <img src="images/01.jpg" alt="" width="200">
    <div>
        <a href="-sharp" onclick="changePic(1)"></a>
        <a href="-sharp" onclick="changePic(2)"></a>
        <a href="-sharp" onclick="changePic(3)"></a>
        <a href="-sharp" onclick="changePic(4)"></a>
        <a href="-sharp" onclick="changePic(5)"></a>
    </div>
</body>
</html>the above code is very simple, the picture every 2 seconds, change, this I understand.
 the question is, when I click on the properties of a, such as travel, why does the picture jump to the travel picture? 
 changePic only returns the number 2 and does not see that it will change the picture? 
 change and changePic are two functions, and changePic cannot call the change function, huh? 
