fix ie8 wrong

@@ -5,8 +5,10 @@
  */
 var $ = require('yoho-jquery');
 
-var areaSelect = {
-    isIE8: window.navigator.appName === 'Microsoft Internet Explorer' && window.navigator.appVersion.match(/8./i) === '8.', // eslint-disable-line
+require('../../common'); // eslint-disable-line
+
+var areaSelect = {  // eslint-disable-line
+    isIE8: window.isIE8,
     init: function($el, areaCode) {
         var city, province, area;
 

@@ -215,6 +215,28 @@ function isLogin() {
     }
 }
 
+function isIE() {
+    return /msie|trident/i.test(navigator.userAgent);
+}
+
+function isIEVer(version) {
+    var ver = '';
+
+    var getVersion = function(regex) {
+        var ua = navigator.userAgent;
+        var match = ua && ua.match(regex);
+
+        return (match && match.length > 1 && match[1]) || '';
+    };
+
+    if (isIE()) {
+        ver = getVersion(/(?:msie |rv:)(\d+(\.\d+)?)/i);
+        return ver === version;
+    }
+
+    return false;
+}
+
 // 品友
 function addPyEvent(eventName, val) {
     if (typeof window.py === 'function') {
@@ -247,6 +269,10 @@ window.registerUrl = registerUrl;
 
 window.jumpUrl = jumpUrl;
 
+window.isIE = isIE;
+
+window.isIE8 = isIEVer('8.0');
+
 window.once = once;
 window.addPyEvent = addPyEvent;