Call external function

Hi all,

looking for some guidance. I am trying to call a js function from within captivate to an external js function on the page. 
i have a button on a slide which evokes a function, save();  

On my html page where the captivate presentation resides, I have a script and a js function called save();

However, the function is not called. I get an error on the console saying save(); is undefined when i click the button on the slide. 

I m thinking I may have to add the script on the html page of the captivate project after its published, but i thought my way should work. Any advice?