Custom Menu

Hello Guys,



I have a custom menu ( ul li menu )





Books | Food | Electronics | Home Made | Other





and I have my Categories



Books

------------>C++

------------>C

-------------------Product1

-------------------Product2

-------------------Product3

------------>Java



Food

------------->Dry Food

------------->Soda

------------->Rice

-------------------Product1

-------------------product2

------------->Deli





The problem is When some one click the link Books I need the menu color to change it to green



if they click on C or C++ ( any subcategory under Books must remain green)



if you click any product under [size=4]Books( including the sub category the link must remain green[/size]





[size=4]i use this method[/size]



{if $category_data.category_id == 1 || $category_data.category_id == 20 }

color :green

{/if}





but the problem is category_id(Books) once i click the subcategory it no longer work or even if I click on a product



I just want diffrent color for each menu item(main category), because I have so many categories





Thanks