The following JavaScript code will automatically load jQuery if it is not already loaded on the current page. This is particularly useful if you need to load jQuery into a bookmarklet. It's also useful in any situation where you can access the JS code on the page but not the HTML code.
// -------------------------------------------------------------------------
// Load JQuery if it's not already loaded.
// -------------------------------------------------------------------------
function loadJQuery() {
//if the jQuery object isn't available
if (typeof(jQuery) == 'undefined') {
// Load jQuery from Google
var fileref=document.createElement('script')
fileref.setAttribute("type","text/javascript")
fileref.setAttribute("src", "http://ajax.googleapis.com/ajax/libs/jquery/1.3.2/jquery.min.js")
document.getElementsByTagName("head")[0].appendChild(fileref);
}
}