解决加入购物车弹窗出现时，页面滑动问题. code review by LZF

@@ -32,6 +32,7 @@ var $chosePanel = $('#chose-panel'),
     queryString,
     $yohoPage = $('.yoho-page');
 
+
 //初始化购物车面板显示
 function init() {
     hasChooseColor = false;
@@ -60,7 +61,19 @@ function checkColorSizeNum() {
     return true;
 }
 
+
 function show(html, cb) {
+    var scrollPosition = [
+            document.documentElement.scrollLeft || document.body.scrollLeft,
+            document.documentElement.scrollTop || document.body.scrollTop
+        ],
+        $html = $('html'); // it would make more sense to apply this to body, but IE7 won't have that
+
+    $html.data('scroll-position', scrollPosition);
+    $html.data('previous-overflow', $html.css('overflow'));
+    $html.css('overflow', 'hidden');
+    window.scrollTo(scrollPosition[0], scrollPosition[1]);
+
     if (html) {
         $chosePanel.html(html);
         if ($('#promotionId').val() !== '') {
@@ -76,6 +89,12 @@ function show(html, cb) {
 
 //隐藏当前Panel
 function hide() {
+    var $html = $('html'),
+        scrollPosition = $html.data('scroll-position');
+
+    // un-lock scroll position
+    $html.css('overflow', $html.data('previous-overflow'));
+    window.scrollTo(scrollPosition[0], scrollPosition[1]);
     $('.chose-panel').hide();
 }