I'm trying to get a page with AJAX, but when I get that page and it includes Javascript code - it doesn't execute it.

Why?

Simple code in my ajax page:

<script type="text/javascript">
alert("Hello");
</script>

...and it doesn't execute it. I'm trying to use Google Maps API and add markers with AJAX, so whenever I add one I execute a AJAX page that gets the new marker, stores it in a database and should add the marker "dynamically" to the map.

But since I can't execute a single javascript function this way, what do I do?

Is my functions that I've defined on the page beforehand protected or private?

** UPDATED WITH AJAX FUNCTION **

function ajaxExecute(id, link, query)
{
    if (query != null)
    {
        query = query.replace("amp;", "");
    }

    if (window.XMLHttpRequest)
    {
        // code for IE7+, Firefox, Chrome, Opera, Safari
        xmlhttp=new XMLHttpRequest();
    }
    else
    {
        // code for IE6, IE5
        xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
    }

    xmlhttp.onreadystatechange=function()
    {
        if (xmlhttp.readyState==4 && xmlhttp.status==200)
        {
            if (id != null)
            {
                    document.getElementById(id).innerHTML=xmlhttp.responseText;
            }
        }
    }

    if (query == null)
    {
        xmlhttp.open("GET",link,true);
    }
    else
    {
        if (query.substr(0, 1) != "?")
        {
            xmlhttp.open("GET",link+"?"+query,true);
        }
        else
        {
            xmlhttp.open("GET",link+query,true);
        }
    }
    xmlhttp.send();
}