trying to call javascript

I changed the function call in my php program to

 $this->load->js("/js/javascript_funcs_extensionloaded.js");
 register_extension();


I am getting error: call to undefined function register_extension()

Now I tried:

echo "<script> register_extension(); </script>";

but need to put a debugger on the extension to see if it actually ran. 

proof that an old dog can learn new tricks