You should change your function to this:
function expandCollapse() {
for (var i = 0; i < arguments.length; i++) {
var element = document.getElementById(arguments[i]);
element.style.display = (element.style.display == "none") ? "inline" :
"none";
}
}
And you should call it onclick
and not in href
<div id="L13a" style="display: inline;"> <a onclick="expandCollapse('L13a', 'L13b');">Lent</a>
</div>
<div id="L13b" style="display: none;"> <a onclick="expandCollapse('L13a', 'L13b');">HI Lent</a>