class inside a class in css? and #

[zeroradius]

I have two questions, i searched both on yahoo but i am bad at coming up with efective querries for searching.

1) is it posibel to do a class inside of a class in css? For example lets say i have a class called .replyCenter and i need it to hold values uniuqe to it for say the input{} and another class .bar is it posibel to do this?

2) A few times i have seen css that looks like this: #dog{} what does # do?

[Orjan]

# is id

[BlaineSch]

1) I'm not sure what you mean by the first question...

<style>
div.one {
color: green;
}
div.one div.two {
color: red;
}
</style>
<div class="one">one
<div class="two">two</div>
</div>
<div class="two">three</div>

That's kinda a class inside of a class? The third div has black text.. untested for spelling errors but the theory works.

2) Orjan is right if it's #name it's the id if it does not have that it's just a regular class.

<style>
.one {
color: green;
}
#two {
color: red;
}
</style>
<div class="one">one</div>
<div id="two">two</div>