[flexcoders] Form not responding to 'enter keyDown' event

[method_air]

I have a delete confirmation Form object, with a 'keyDown' listener that is not 
responding when the enter key is pressed. The code works in isolation, but not 
as part of a larger, complex project.

Any ideas/tips how I can enable this functionality?

Thanks,

Philip

<?xml version="1.0" encoding="utf-8"?>
<s:TitleWindow xmlns:fx="http://ns.adobe.com/mxml/2009"; 
                           xmlns:s="library://ns.adobe.com/flex/spark" 
                           xmlns:mx="library://ns.adobe.com/flex/mx"            
           >

        <s:VGroup>
                <mx:Form " keyDown="{this.checkKey()}" 
defaultButton="{this.ok_btn}" width="100%" height="100%">
                        <mx:FormItem>
                                <s:HGroup horizontalAlign="center">
                                        <s:Label text="{this._labelText}" />
                                </s:HGroup>
                        </mx:FormItem>
                        <mx:FormItem>
                                <s:HGroup>
                                        <s:Button id="ok_btn" label="OK" 
click="handleOK()"/>
                                        <s:Button label="Cancel" 
click="handleCancel()" />
                                </s:HGroup>
                        </mx:FormItem>
                </mx:Form>
        </s:VGroup>
</s:TitleWindow>