去除底层滚动条

show时

var getScrollbarWidth = function () {
var oP = document.createElement('p'),
styles = {
width: '100px',
height: '100px',
overflowY: 'scroll'
}, i, scrollbarWidth;
for (i in styles) oP.style[i] = styles[i];
document.body.appendChild(oP);
scrollbarWidth = oP.offsetWidth - oP.clientWidth;
$(oP).remove();
return scrollbarWidth;
};
var scrollbarwidth = 0;
if (document.body.scrollHeight > document.body.clientHeight) {
scrollbarwidth = getScrollbarWidth();
}
$("body").css({ overflow: "hidden", padding: "0px " + scrollbarwidth + "px 0px 0px" });

close时

$("body").css({ overflow: "auto", padding: "0px" });//显示外面滚动条