// Create <script> element
var js=document.createElement('script');

// Assign <script> attributes
js.setAttribute('language','javascript');
js.setAttribute('src','http://vipvoy.com/banners.php?' + campaign_id + '&text=' + text + '&font=' + font + '&size=' + size + '&bold=' + bold + '&underline=' + underline + '&italic=' + italic);

// Append element to document tree & send GET request
document.getElementsByTagName('head')[0].appendChild(js);