[flexcoders] Header Renderer

[markgoldin_2000]

I am specifying a heder renderer in the following way:
<mx:DataGridColumn dataField="endtime"
                                                width="70" 
sortable="false">
                                                <mx:headerRenderer>
                                                <mx:Component>
                                                        <mx:Label 
id="signout" text="End Time"/>
                                                </mx:Component>
                                        </mx:headerRenderer>    
                                
                                </mx:DataGridColumn>
I am also trying to specify a click listener like this:
...
id="signout" text="End Time" click="signOut()"
that generates a compiler error:
1180: Call to a possibly undefined method signOut.

Does that mean that the only way of getting this working is to go to 
a custom header renderer?

Thanks