function addMochaSearchEngine()
{
    return addOpenSearch("Mocha", "gif", "g");
}

// copied from http://mycroft.mozdev.org/developer/hosting.html
function addOpenSearch(name,ext,meth)
{
    if ((typeof window.external == "object") && 
        ((typeof window.external.AddSearchProvider == "unknown") || 
         (typeof window.external.AddSearchProvider == "function"))) {
         
        if ((typeof window.external.AddSearchProvider == "unknown") && meth == "p") {
            alert("This plugin uses POST which is not currently supported by Internet Explorer's implementation of OpenSearch.");
        } else {
            window.external.AddSearchProvider("http://mycroft.mozdev.org/externalos.php/" + name + ".xml");
        }
        
    } else {
        alert("Sorry, your browser doesn't support OpenSearch search plugins.");
    }
}