texthistory script compability, need help

[thehacker]

I tried to use textHistory script from the cookbook of renpy because I wanted my game to use that for rollback
link: http://www.renpy.org/wiki/renpy/doc/coo ... xt_History

but I have one problem that is when I want to use mousewheel down to advance by using this script

config.keymap["dismiss"].append("mousedown_5")

It won't work!!
if I delete/remove the textHistory script it works as usual

I have some experience with programming but not that well with python and the API used here, I've read the textHistory script but can't find anything that relate to advancing the text nor mousedown_5

Can anyone help me to find what the problem is