Each course description includes one line that is always visible and a div containing course details which is invisible by default and shown when the user clicks on the word "details" beside the course title in the line that is always visible.
I wanted to make the course title itself act as a toggle as well as the word "details". I tried directly invoking the hide-show function and also invoking the onclick event of the "details" button, but in both cases because the details button was a child item of the title line object doing the calling, the onclick bubbled up which meant that the method was called twice so the apparent effect was that nothing happened. Then I restructured the XHMTL so that the course title is a sibling of the details button and both contained in a div, then invoking the method worked fine.