[flexcoders] Get id of what called the event.

[timgerr]

How can I get from an event the id of a flex item,
<mx:Form>
                <mx:FormItem label="User Name" required="true">
                        <mx:TextInput name="User Name" id="userName"/>
                </mx:FormItem>
                <mx:FormItem label="Password" required="true">
                        <mx:TextInput id="password"/>
                </mx:FormItem>
        </mx:Form>
        <mx:Button id="loginBtn" click="GetID(event)" label="Login" x="99"
y="90"/>

Here is the function that I want to create
public function GetEvtID(event:event){
     trave(event.id);
}

How with the event trigger can I get the id of what called the event.

Thank you,
timgerr