placeholder兼容IE8代码

//需要引入jQuery

$(function(){

       handlePlaceholderForIE();

});

function handlePlaceholderForIE() {

    if (jQuery.browser.msie && jQuery.browser.version.substr(0, 1) <= 9) {

        // ie7&ie8

        jQuery('input[placeholder], textarea[placeholder]').each(function () {

            var input = jQuery(this);

            jQuery(input).val(input.attr('placeholder'));

            jQuery(input).focus(function () {

                if (input.val() == input.attr('placeholder')) {

                    input.val('');

                }

            });

            jQuery(input).blur(function () {

                if (input.val() == '' || input.val() ==     input.attr('placeholder')) {

                    input.val(input.attr('placeholder'));

                }

            });

        });

    }

}