<script>

function change_pic() {

var imgObj = document.getElementById("caocao_pic");

if (imgObj.getAttribute("src", 2) == "../img/jpg/1.png") {

imgObj.src = "img/jpg/2.png";

} else {

imgObj.src = "../img/jpg/1.png";

}

}

</script>

<img

src="../img/jpg/1.png"

class="wujiang_pic_size"

id="caocao_pic"

onClick="change_pic()"

/>