Client-side requests must all be made using GlideAjax with a callback function.
Using .getXMLWait() is not adviced anymore since it blocks the client-side execution thread.
The SNOW helper makes it possible to write the complete request as a simple one-liner.
SNOW.get(scriptInclude,functionName,sysParamObj,cb);scriptInclde [string] The name of the ScriptInclude you are refering to.