Resize Div - javascript ?

Hi.

i need to resize a div height on mouse over or on click on a link.
i found the collapsible div mootools script but that one hides the div completely.
what i want is to have the div visible (like 50px height) and resize it to 400px.

is there any tutorial or do someone know how to do that ?


Greetings

jQuery have lot of candy too. http://dev.iceburg.net/jquery/jqDnR/

// http://docs.jquery.com/Using_jQuery_with_Other_Libraries

thx, i found what i need in Mootools.

Mootools, jQuery, mac, pc... 

http://blog.themeforest.net/screencasts/jquery-for-absolute-beginners-video-series/