Hide/Show Content on Mouse Click

<script>
function showHideDiv(id){
  var obj = document.getElementById(id);
    if (obj.style.display=="none"){
      obj.style.display='block';
    } else if(obj.style.display=="block"){
      obj.style.display='none';
    }
}
</script>
<a href="#" onclick="showHideDiv('div-1')">
Click here to Show more info
</a><br />
<div id="div-1" style="display:none;">
Here is the extra content
</div>