jq自己再找吧
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title></title>
</head>
<body>
<div class="img">
<img src="img/c1.jpg" >
</div>
</body>
</html>
<script src="js/jquery.min.js"></script>
<script>
$(".img").click(function(){
if($('.img img').attr('src')=='img/c1.jpg'){
$('.img img').attr('src','img/c2.jpg');
}else{
$('.img img').attr('src','img/c1.jpg');
}
})
</script>