想要消除输入文本框的默认值

AJa*_*arg 0 html javascript textbox

如果我提出这个问题我错了,请不要投反对票.我有一个像这样的TextBox:

<input class="login-inpt" runat="server" name="loginName" type="text" value="User Name" />
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它目前拥有默认值.我希望在单击TextBox时清除默认值并用光标替换.

kay*_*yz1 8

对于较新的浏览器(IE> 9):

<input type="text" id="userName" placeholder="User Name" />
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对于老年人:

<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
    <title>Placeholder support</title>
</head>
<body>
    <input type="text" id="userName" placeholder="User Name" />

    <script src="../js/vendor/jquery-1.10.2.min.js"></script>
    <script src="../js/vendor/jquery-migrate-1.2.1.js"></script>
    <script src="../js/vendor/modernizr-latest.js"></script>
    <script src="../js/placeholder.js"></script>
</body>
</html>
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placeholder.js(jQuery,Modernizr)

var Placeholder = (function ($, document) {

    /* Static Content */
    var _$document = $(document);

    /* Events */
    var _initPlaceholders = function () {
        _$document.find('input:text').each(function () {
            var $this = $(this);
            $this.css({ color: '#888' }).val($this.attr('placeholder'));
        });
    };

    var _placeholderEvent = function () {
        var $input = $(this), placeholderValue = $input.attr('placeholder');

        if ($input.val() === placeholderValue) {
            $input.css({ color: '#000' }).val('');
            return;
        }

        if ($input.val() === '') {
            $input.css({ color: '#888' }).val(placeholderValue);
        }
    };

    var _bindEvents = function () {
        if (!Modernizr.input.placeholder) {
            _initPlaceholders();
            _$document.on('focus blur', 'input:text', _placeholderEvent);
        }
    };

    var init = function () {
        _bindEvents();
    };

    return {
        init: init
    };
})(jQuery, document);

Placeholder.init();
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