show a static block just when visitor's GeoIP is from GB

Question

I need to change the content of a static block in magento for visitors from some special countries.

This is the JavaScript embedded into the Magento:

<script src="http://j.maxmind.com/app/country.js" charset="ISO-8859-1"></script>

I use the following code in my static block :

if (geoip_country_code() == 'GB') 
    {
      alert("Hello, you are in Great Britain");
    }

But when i save this static block, magento changes it to this:

<p>if (geoip_country_code() == 'GB') { alert("Hello, you are in Great Britain"); }</p>

??!!

What should i do to determine the GeoIP of the visitors and change the Content to be shown in an static block?