Script not working

[DoctorSubtilis]

Today I tried to use your script, but unsuccessfully. Could you explain what steps I should do?

1. linked your js file (from local) and jquery (from the Net),

2. added the script (in html head):

   $(function() {
   $("img.scale").imageScale();
   });
   

3. added the html code -> class="scale" data-scale="best-fit-down" data-align="center" in the child element (an image)

But the child img element didn't fit to the parent element...