diff --git a/JavaScriptCore-Demo/JSCallOC/JSCallOC.html b/JavaScriptCore-Demo/JSCallOC/JSCallOC.html
index 6a06330..a4fcfa9 100644
--- a/JavaScriptCore-Demo/JSCallOC/JSCallOC.html
+++ b/JavaScriptCore-Demo/JSCallOC/JSCallOC.html
@@ -70,7 +70,7 @@
             <br/>
             <br/>
             
-            <input type="button" value="oc原生Alert" onclick="alert('alert');" />
+            <input type="button" value="oc原生Alert" onclick="alert('msg from js');" />
             <br/>
             <br/>
             
diff --git a/JavaScriptCore-Demo/JSCallOC/JSCallOCViewController.m b/JavaScriptCore-Demo/JSCallOC/JSCallOCViewController.m
index f8290c7..3cb66c2 100644
--- a/JavaScriptCore-Demo/JSCallOC/JSCallOCViewController.m
+++ b/JavaScriptCore-Demo/JSCallOC/JSCallOCViewController.m
@@ -72,8 +72,12 @@ - (void)webViewDidFinishLoad:(UIWebView *)webView
     self.context[@"alert"] =
     ^(NSString *str)
     {
-        UIAlertView *alert = [[UIAlertView alloc]initWithTitle:@"msg from js" message:str delegate:nil cancelButtonTitle:@"ok" otherButtonTitles:nil, nil];
-        [alert show];
+        //要把改变视图的操作放到主线程中，否则就会抛出异常，对以后的操作会有问题
+        [[NSOperationQueue mainQueue]addOperationWithBlock:^{
+            
+            UIAlertView *alert = [[UIAlertView alloc]initWithTitle:@"提示" message:str delegate:nil cancelButtonTitle:@"确定" otherButtonTitles:nil, nil];
+            [alert show];
+        }];
     };
     
     __block typeof(self) weakSelf = self;
diff --git a/README.md b/README.md
index 64cfc26..edff5ea 100644
--- a/README.md
+++ b/README.md
@@ -2,3 +2,14 @@ JavaScriptCore-Demo
 ===================
 
 JavaScriptCore.framework ：iOS7 中新加入的框架，用来处理JavaScript。JavaScriptCore 是苹果 Safari 浏览器的 JavaScript 引擎，JavaScriptCor在 OS X 平台上很早就存在的，而在 iOS 平台，直到IOS7才对外开放，并提供了 Objective-C 的接口
+
+====================
+Edited by Winzlee 
+
+注：在JSCallOC中，当创建原生的UIAlertView的时候，需要把代码放到主线程中，否则就会因为在后台修改了视图而抛出异常，会在以后的操作中有影响。
+
+        [[NSOperationQueue mainQueue]addOperationWithBlock:^{
+            
+            UIAlertView *alert = [[UIAlertView alloc]initWithTitle:@"提示" message:str delegate:nil cancelButtonTitle:@"确定" otherButtonTitles:nil, nil];
+            [alert show];
+        }];