Property value getting null in beforeRenderResponse

[Dushyant Agarwal]

Hi,
I have a project with a JSF page containing the <f:phaseListener> tag with its binding attribute equal to its own backing bean , which means the Page's Backing Bean is a PhaseListener.

Now there is a beforeRenderResponse() method implemented in the backing bean which gets called just before the before the RENDER_RESPONSE phase gets executed.

As well as there is a String Property str(initiallly str= null). Its value is set in an action method bound to a <h:commandButton> on the page(this would take place in Invoke application phase - before the Render Response phase) ,
to a String as following .

str=" myvalue";

But when I try to print the value of str in beforeRenderResponse() It comes out to be null. Where does the value of str get changed if no new bean instance is created??