Flex错误:找不到类型或类型不是编译时常量

我的flex代码中出现了以下错误。有什么办法解决这个问题吗?

<mx:Script>
    <![CDATA[
        private function send_data():void {
            userRequest.send();
        }
    ]]>
</mx:Script>
<mx:Form x="22" y="10" width="493">
    <mx:HBox>
        <mx:Label text="UserId"/>
        <mx:TextInput id="userid"/>
    </mx:HBox>
    <mx:HBox>
        <mx:Label text="Ip Address"/>
        <mx:TextInput id="ip"/>
    </mx:HBox>
    <mx:Button label="Submit" click="send_data()"/>
</mx:Form>
<mx:DataGrid id="dgUserRequest" x="22" y="128" dataProvider="{userRequest.lastResult.users.user}">
    <mx:columns>
        <mx:DataGridColumn headerText="User ID" dataField="userid"/>
        <mx:DataGridColumn headerText="User Name" dataField="ip"/>
    </mx:columns>
</mx:DataGrid>
<mx:TextInput x="22" y="292" id="selectedemailaddress"
    text="{dgUserRequest.selectedItem.emailaddress}"/>
<mx:HTTPService id="userRequest" url="http://localhost/post.php" useProxy="false" method="POST" resultFormat="e4x">
    <mx:request xmlns="">
        <userid>{userid.text}</userid>
        <ipaddress>{ip.text}</ipaddress>
    </mx:request>
</mx:HTTPService>

Type was not found or was not a compile-time constant: data.
[Generated code (use -keep to save): Path: data-generated.as, Line: 245, Column: 14]