Load jQuery If Not Loaded

// My Solution To Load jQuery From Your Script File If It Isn't Already Loaded!!!!!

window.$ && main() || (function() {
    var jquery = document.createElement("script");
    jquery.setAttribute("type","text/javascript");
    jquery.setAttribute("src","jquery.js");
    jquery.onload = main;
    jquery.onreadystatechange = function() {
        if (this.readyState == "complete" || this.readyState == "loaded") main();
    };
    (document.getElementsByTagName("head")[0] || document.documentElement).appendChild(jquery);
})();

function main() {
// run your website's script
}


// jQuery's Implementation Of This On Wikipedia [ Just Noticed This :( ]
// Just to make things clear this does not serve the same purpose as my solution and wouldn't work without some modification.
http://en.wikipedia.org/wiki/JQuery

if(!(window.jQuery && window.jQuery.fn.jquery == '1.6.2')) {
    var s = document.createElement('script');
    s.setAttribute('src', 'http://ajax.googleapis.com/ajax/libs/jquery/1.6.2/jquery.min.js');
    s.setAttribute('type', 'text/javascript');
    document.getElementsByTagName('head')[0].appendChild(s);
}