I’m using this:
http://www.w3schools.com/jquery/tryit.asp?filename=tryjquery_toggle
the thing here is that i change the button to an transparent image.
and i want the image to change when the the <div> is hidden.
for example:
The image is a arrow pointing down (when i click the arrow i want the image to disappear)
and i want a new image pointing up to show the <div>.
If you dont understand i have a image here:

that’s what is happening now; you see that even when my div is hidden it show the “hide div button”.
In the image below you can see what i want!
I want the image to chane when the is hidden to “show div”.
Remenber that the image is .png

You can just use an toogle from one of the effects like fade and slide.
Like this:
See how it works
I personally don’t like the toggle function, so I kind of just make my own.
I know you want to use an image, but you can still do this with a little change in the code.