How do I navigate 'back' dynamically ?

How do I navigate 'back' dynamically ?

I can navigate dynamically using:      
     
$.mobile.navigate('#' + pageId);

But how do I get the reverse animation?

I have tried the below but I see no change :-(
 
$.mobile.navigate('#' + pageId, { reverse: true }); and
$.mobile.navigate('#' + pageId, { direction: back });