Zoom not as i expected

I have applied a zoom code to my site but its not working as i expected.
The page in question is http://www.theremotedoctor.co.uk

My issues that i need some help with if i may are as follows,
The zoom is applied to the Honda Epc.
It zooms fine BUT can it be made to zoom center of screen because at the moment depending where the honda epc is on the screen,the zoomed image is also in a different position each time.

I understand its the type of code i have used but is there some code that allows the photo to zoom without making the original page behind toggle when zooming.
I suppose i mean can the photo be zoomed whilst the rest of the page behind the zoomed image stay the same size.
This can be seen by the Paypal logo & Dr logo being moved up & down the page whilst the zoom feature is in action.
Please advise the codes i need to add to achieve my goal

Many thanks.