js代码

<script src="js/jquery.min.js"></script>
<script>$("html").css("font-size", 20 * ($(window).width() / 640) + 'px');</script>
<script>
    window.onload = function() {
        var arrIcon = ['images/1.jpg', 'images/2.jpg'];
        var num = 0; //控制头像改变
        var iNow = -1; //用来累加改变左右浮动
        var icon = $('#user_face_icon')[0].getElementsByTagName('img');
        var btn = $('#btn')[0];
        var text = $('#text');
        var content = $('.content')[0];
        var img = content.getElementsByTagName('img');
        var span = content.getElementsByTagName('span');
        var i = content.getElementsByTagName('i');
        icon[0].onclick = function() {
            if (num == 0) {
                this.src = arrIcon[1];
                num = 1;
            } else if (num == 1) {
                this.src = arrIcon[0];
                num = 0;
            }
        }

        btn.onclick = function() {
            if (text.html() == '') {
                alert('不能发送空消息');
            } else {
                content.innerHTML += '<li><img src="' + arrIcon[num] + '"><span>' + text.html() + '</span><i>已读</i></li>';
                iNow++;
                if (num == 0) {
                    img[iNow].className += 'imgright';
                    span[iNow].className += 'spanright';
                    i[iNow].className += 'iright'
                } else {
                    img[iNow].className += 'imgleft';
                    span[iNow].className += 'spanleft';
                    i[iNow].className += 'ileft'
                }
                text.html('');
                // 内容过多时,将滚动条放置到最底端
                content.scrollTop = content.scrollHeight;
            }
        }
    }
</script>