update the flex support detecting method. code review by Guanning

@@ -16,7 +16,6 @@ var introUrl = $('#introUrl').val(),
     end = false;
 
 var sizeSwiper,
-    d = document.documentElement.style
     refSwiper;
 
 
@@ -38,6 +37,18 @@ function hiddenTips($ele) {
     }
 }
 
+function isFlexSupport() {
+    var flex = document.createElement('p').style.flex,
+        webkitFlex = document.createElement('p').style.webkitFlex,
+        flexWrap = document.createElement('p').style.flexWrap;
+
+    if ((flex === '' || webkitFlex === '') && flexWrap === '') {
+        return true;
+    } else {
+        return false;
+    }
+}
+
 
 function search() {
     if (searching || end) {
@@ -73,7 +84,7 @@ function search() {
             hiddenTips($('#size-swiper-container'));
             hiddenTips($('#reference-swiper-container'));
 
-            if (('flexWrap' in d) || ('WebkitFlexWrap' in d))) {
+            if (!isFlexSupport()) {
                 $('.detail .column').removeClass('column').addClass('oldbox');
             }
             searching = false;