原创-兼容IE8的placeholder

!function (o) {
    o.fn.extend({
        PlaceHolder: function () {
            var _isEmpty = function (val) {
                return (val === "" || val === "null" || val === null || val === "undefined" || val === "NaN");
            };
            var _handler = function (obj, event, callback) {
                obj.addEventListener ? obj.addEventListener(event, callback, false) : obj.attachEvent && obj.attachEvent("on" + event, callback, false)
            };
            var _support = function () {
                return "placeholder" in document.createElement("input")
            };
            var $this = this;
            if (!_support()) {
                $this.each(function ($index, $el) {
                    (function (item) {
                        var t = item.getAttribute("placeholder");
                        if(!_isEmpty(t)){
                            item.value = t;
                            _handler(item, "focus", function () {
                                if (item.value === t) {
                                    item.value = ""
                                } else {
                                    return false
                                }
                            });
                            _handler(item, "blur", function () {
                                if (item.value === "") {
                                    item.value = t
                                } else {
                                    return false
                                }
                            });
                        }
                    })($el)
                })
            } else {
                return
            }
        }
    })
}(window.$ || jQuery);

调用方式：

$(".input1,input2").PlaceHolder();

源码下载地址：http://www.mengxiangchaoren.com/js/jquery.placeholder.1.0.0.min.js