[Solved] and

Please show more about your problem detail like paste your error code in here that we could use those information to help you.

Btw, base_url() isn’t a php embedded function, one of the potential problem is that your friend custom a function named base_url() that supposed to return it’s root path.
So, you have to either include or build the same function with the same name to your script.

Ex.

function base_url()
{
  return dirname($_SERVER['SCRIPT_FILENAME']);
}

And the ‘src’ inside your tag should point to your jQuery source file.