html content inside span using javascript
===

I have a span and 5 different html structures which basically involve lists and divs.

I have 5 buttons. Clicking on each button should change the content of the span to one of these structures.

I know that it can be done as easily as using 
    
    document.getElementById("a").innerHTML = "<div> A </div>";

But if I have an html structure of 20-30 lines, is this the best approach? Or is there any better way?