In this case:
- main image must have only onmouseover actions (no onclick, no onmouseout etc.):
DISPLAY (this image, hide)
DISPLAY (mouseover image)
- onmouseover image must have onclick (this is your actions) and onmouseout actions:
DISPLAY (this image, hide)
DISPLAY (main image)
If you want to use other events - also be aware of using actions attached to unnecessary events.
In this case:
- main image must have only onmouseover actions (no onclick, no onmouseout etc.):
DISPLAY (this image, hide)
DISPLAY (mouseover image)
- onmouseover image must have onclick (this is your actions) and onmouseout actions:
DISPLAY (this image, hide)
DISPLAY (main image)
If you want to use other events - also be aware of using actions attached to unnecessary events.