Limesurvey uses JQuery, and you are spoilt for choices for plugins, or you can code the effect you want.
The easiest solution will be to through the plugin into the directory structure, then use javascript code to implement the effect you seek.
You can get started here: manual.limesurvey.org/wiki/Workarounds:_...ime_using_Javascript
The easiest solution will be to through the plugin into the directory structure, then use javascript code to implement the effect you seek.
You can get started here: manual.limesurvey.org/wiki/Workarounds:_...ime_using_Javascript