(function ($) {            if (!document.defaultView || !document.defaultView.getComputedStyle) {                var oldCurCSS = jQuery.curCSS;                jQuery.curCSS = function (elem, name, force) {                    if (name === ‘background-position‘) {                        name = ‘backgroundPosition‘;                    }                    if (name !== ‘backgroundPosition‘ || !elem.currentStyle || elem.currentStyle[name]) {                        return oldCurCSS.apply(this, arguments);                    }                    var style = elem.style;                    if (!force && style && style[name]) {                        return style[name];                    }                    return oldCurCSS(elem, ‘backgroundPositionX‘, force) + ‘ ‘ + oldCurCSS(elem, ‘backgroundPositionY‘, force);                };            }            var oldAnim = $.fn.animate;            $.fn.animate = function (prop) {                if (‘background-position‘ in prop) {                    prop.backgroundPosition = prop[‘background-position‘];                    delete prop[‘background-position‘];                }                if (‘backgroundPosition‘ in prop) {                    prop.backgroundPosition = ‘(‘ + prop.backgroundPosition + ‘)‘;                }                return oldAnim.apply(this, arguments);            };            function toArray(strg) {                strg = strg.replace(/left|top/g, ‘0px‘);                strg = strg.replace(/right|bottom/g, ‘100%‘);                strg = strg.replace(/([0-9\.]+)(\s|\)|$)/g, "$1px$2");                var res = strg.match(/(-?[0-9\.]+)(px|\%|em|pt)\s(-?[0-9\.]+)(px|\%|em|pt)/);                return [parseFloat(res[1], 10), res[2], parseFloat(res[3], 10), res[4]];            }            $.fx.step.backgroundPosition = function (fx) {                if (!fx.bgPosReady) {                    var start = $.curCSS(fx.elem, ‘backgroundPosition‘);                    if (!start) {//FF2 no inline-style fallback                        start = ‘0px 0px‘;                    }                    start = toArray(start);                    fx.start = [start[0], start[2]];                    var end = toArray(fx.end);                    fx.end = [end[0], end[2]];                    fx.unit = [end[1], end[3]];                    fx.bgPosReady = true;                }                var nowPosX = [];                nowPosX[0] = ((fx.end[0] - fx.start[0]) * fx.pos) + fx.start[0] + fx.unit[0];                nowPosX[1] = ((fx.end[1] - fx.start[1]) * fx.pos) + fx.start[1] + fx.unit[1];                fx.elem.style.backgroundPosition = nowPosX[0] + ‘ ‘ + nowPosX[1];            };        })(jQuery);

$(selecter).css({ backgroundPosition: ‘(20px 0)‘ });
//支持动画
$("#viewBody").animate({ backgroundPosition: ‘(‘+my+‘)‘ });