First, let me just say that I love this plugin! Am currently having one small intermittent hard to isolate issue that's probably use-case specific that I emailed you aboutt but other than that it's working great!
Anyway, I think it'd be great if you could tab up or hit the arrow up button or tab down / hit arrow down to change your position within the scrollbar. I do it all the time on sites using the browsers scroll bar and think it'd be useful if it could be done with this scrollbar as well.
I don't know when/if keyboard navigation will be implemented within the script but I've done an example that you can check and use in your implementation:
Thanks for your comments and feedback :)
Love it - thanks!!
how can we change the image for the arrows?
You can change the arrows images in jquery.mCustomScrollbar.css (line 161). You can either use the sprites and change the background-position or use your own images.