[jQuery] basic problem css

[^andrea^]

Hi everybody,

I'm a new jQuery user and I'm already having some trouble... :-|

simply, I've got a menu:

<ul class="main_menu">
   <li class="main_menu" id="menu_id0" >
                        <a href="#Homepage">Homepage</a>
   </li>
   <li class="main_menu" id="menu_id1" >
                <a href="#application_1">ONE</a>
   </li>
   <li class="main_menu" id="menu_id2" >
                        <a href="#application_2">TWO</a>
   </li>
   <li class="main_menu" id="menu_id3" >
                        <a href="#application_3">THREE</a>
   </li>
   <li class="main_menu" id="menu_id4" >
                        <a href="#application_4">FOUR</a>
   </li>
</ul>

and I want to change the background-color of the buttons anytime I
change the application...
When I load the website I'll be in the homepage so I want that button
red and the others blue...
when I select application 1, this button red and the others blue...
and so on!!!

actually, now, I'm just trying to change the color of the homepage
button when I load the page and I do this:

$(document).ready(function(){
$("#menu_id0").css({ background-color:"red" });
});

but Firebug tells me:
missing : after property id
[Break on this error] $("#menu_id0").css({ background-color:"red" });
\n

and anyway, it doesn't work at all...

any idea?

I hope someone will waste his time to answer... ;-)

cheers