So I am trying to assign a value to a property in my controller and it just is not working, the value always ends up as null... am I doing somethign wrong?

In My Controller

public Boolean blnDoAttachment{get; set;}

 <<Some Code>>

return new PageReference('p/attach/NoteAttach?pid=/' + c.id + 'retURL=' + c.id); 

}

return new PageReference('/'+ c.id);

return null;

On My VisualForce Page

<apex:commandButton action="{!save}" value="Submit"><apex:param value="False" assignto="{!blnDoAttachment}"/></apex:commandButton> <apex:commandButton action="{!save}" value="Submit and Attach"><apex:param value="True" assignto="{!blnDoAttachment}"/></apex:commandButton>

Any assistance would be greatly appreciated.  I am pretty sure its just something totally stupid on my part

Thanks!