Minimization of boxes only by pushing the green button

I would like to change the javascript code for the minimization of the boxes on the right side, because currently you can click anywhere on the top of the box to hide the content, what means the green button is only there for the general design. I wonder if it is possible with HTML (< map > < area >), but I think I should try to modify the javascript (itheme.ui.js) and I'm not very good at that, so if somebody know a good trick to fix that issue, it would be very nice.