jQuery toggle CSS?

I want to toggle between CSS so when a user clicks the button (#user_button) it shows the menu (#user_options) and changes the CSS, and when the user clicks it again it goes back to normal. So far this is all I have:

$('#user_button').click( function() {
    $('#user_options').toggle();
    $("#user_button").css({    
        borderBottomLeftRadius: '0px',
        borderBottomRightRadius: '0px'
    }); 
    return false;
});

Can anybody help?

For jQuery versions lower than 1.9 (see https://api.jquery.com/toggle-event):

$('#user_button').toggle(function () {
    $("#user_button").css({borderBottomLeftRadius: "0px"});
}, function () {
    $("#user_button").css({borderBottomLeftRadius: "5px"});
});

Using classes in this case would be better than setting the css directly though, look at the addClass and removeClass methods alecwh mentioned.

$('#user_button').toggle(function () {
    $("#user_button").addClass("active");
}, function () {
    $("#user_button").removeClass("active");
});