I have checked your page and as far as I can see you have installed the script properly. The reason why it doesn't work is that you haven't install jQuery library, which is required for the script work.
In order to install jQuery library on your site you should place following code before </head> tag.
Code:
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.3.2/jquery.min.js" type="text/javascript"></script>
Once you do this, the script will work as expected.
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Maria Nikiforova, Ecwid Team
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