Mootools Toogle DIV Effect

I have a simple mootools toogle script which show 1 div, while concealing others.
Which works perfectly but its animation is very boring and simple…

Can somebody help making it a fancy? Like slide in or fade in/fadeout?

JS:

lastone='empty'; 
function showIt(lyr) 
{ 
if (lastone!='empty') lastone.style.display='none'; 
lastone=document.getElementById(lyr); 
lastone.style.display='block';

}

html:



<a href="JavaScript:;" onClick="showIt('topnavsearch')"; ">search</a>

<div id="topnavsearch" style="display:none;">
  Search block  
</div>


Mootools have the answer on there site

http://mootools.net/docs/core/Fx/Fx
http://demos.mootools.net/Effects

SgtLegend thank you for the help… but i sucks in javascript esp mootools… can you help?