images in dialog header

[fiktion]

Does anyone know if this is supported? I am trying to put an image in the header of a dialog. I have searched the forums and the documentation and there is no mention of putting an image up there. I tried using a facet but that is not working. My code example is blow.

<p: dialog widgetVar="help" zindex="10" >
<f:facet name="header">
<img src="./imgs/help.png" />
</f:facet>
</p:dialog>