Going back to previous message (bitmap) during instructions

Dear all, 

I am trying to implement the possibility to go back to the previous message(s) when navigating through my experiment's instructions. As for now, this is the code that I have: 

message i0 mouse

message i0b mouse

message i1 mouse
etc. etc.

So, using 'mouse' enables clicking to continue to the next message. However, is there any chance of returning to the previous message? What should the code look like? 

Many thanks in advance, 

Best,
Silvano