javascript code for Collapsible and Extendable

HI:

Can any one send me Javascript code to Collapsible and Exdendable menu for the following Scenario

1 .My task is i have 2 categories namely Car,Bike.Categorey Car has subcategory Benz,Sonata .

2 similarly the Bike has subcategorey Yamaha,Herohonda.

3 while clicking the category Car the subcategories Benz,Sonata has to open

4 Then when categorey Bike is clicked the subcategorey Yamaha,Herohonda has to be opened 5

5 At the same time already opened subcategory Benz,Sonata should be closed.

My code is given below:

Objective is when clicking the categorey particular subcategorey should be opned .please treate this mail is very very urgent and send me code.

My Code:

<table>

<tr >

<div>

<a href="#">Benza> <br />

<a href="#">Sonataa>

div>

td>

tr>

<tr >

<td >

<a href="#">Bikea>

<div >

<a href="#">Pulsara> <br />

<a href="#">Hondaa>

div>

td>

tr>

table>

Thanks