// Either embed this funtion in the , or load it from an external file. // function set_iframe_source() { var args = new Object( ); // Get query string var query = location.search.substring(1); if (query == "") { document.getElementById('books_frame').src = "http://www.jsworldwide.com/books/illo_feed.html"; } else { // Break at ampersand, in case there are other parameters var pairs = query.split("&"); for(var i = 0; i < pairs.length; i++) { // Look for "name=value" var pos = pairs[i].indexOf('='); // If not found, skip if (pos == -1) continue; // Extract the name var argname = pairs[i].substring(0,pos); // Extract the value var value = pairs[i].substring(pos+1); // Store as a property args[argname] = unescape(value); } document.getElementById('books_frame').src = args["iframe_source"]; } alert(getElementById('books_frame').src); }