购物车修改

@@ -10,6 +10,8 @@ var $footer = $('#yoho-footer'),
     $yohoPage = $('.yoho-page'),
     $header = $('.yoho-header');
 
+var backToTopHammer;
+
 function cookie(name) {
     var cookies = document.cookie,
         cookieVal,
@@ -158,8 +160,8 @@ function reMarginFooter(fixedElement) {
     });
 
     if ($op.find('.back-to-top').length > 0) {
-        navHammer = new Hammer(document.getElementsByClassName('back-to-top')[0]);
-        navHammer.on('tap', function(e) {
+        backToTopHammer = new Hammer(document.getElementsByClassName('back-to-top')[0]);
+        backToTopHammer.on('tap', function(e) {
             $(window).scrollTop(0);
             return false;
         });