采用JQuery实现文本框的水印效果非常容易，效果如下：
代码片段，定义要应用水印效果的文本框的样式： .watermark { color: #cccccc; }
将JavaScript代码封装成JQuery的插件：
(function ($) { $.fn.watermark = function (options) { var settings = $.extend({ watermarkText: "Input something here", className: "watermark" }, options); return this.each(function () { if ($(this).val().length == 0 || $(this).val() == settings.watermarkText) { //init, set watermark text and class $(this).val(settings.watermarkText).addClass(settings.className); } //if blur and no value inside, set watermark text and class again. $(this).blur(function () { if ($(this).val().length == 0) { $(this).val(settings.watermarkText).addClass(settings.className); } }); //if focus and text is watermrk, set it to empty and remove the watermark class $(this).focus(function () { if ($(this).val() == settings.watermarkText) { $(this).val('').removeClass(settings.className); } }); }); } })(jQuery);
接下来直接在页面上使用：
<div> <input type="text" /> </div> <script type="text/javascript"> $(document).ready(function () { $("#tb_search").watermark({ watermarkText: "站内检索", className: "watermark", }); }); </script>