[jQuery] Hide button based on combo value

[ciupaz]

Hi all,
I have a select option like this:

<select id="color" name="color">
       <option value="">Select a color</option>
       <option value="1">Red</option>
       <option value="2">Green</option>
       <option value="3">Blue</option>
       <option value="4">White</option>
       <option value="5">Black</option>
</select>


and a button:

<div id="buttons" class="sportelloamiacque_formline">
    <input type="submit" id="submitButton" name="submitButton"
value="Continue" />
</div>

How can I hide the button is the combo has "Select a color" selected,
and show the button when the user select a color?

Thanks in advance.

Luis