<script>
function show(id){
document.getElementById(id).style.display="block";
}
</script>
<a href="javascript:void(0)" onClick="show('e1')" >1</a>
<a href="javascript:void(0)" onClick="show('e2')">2</a>
<a href="javascript:void(0)" onClick="show('e3')">3</a>
<div style="display: none" id="e1">1</div>
<div style="display: none" id="e2">2</div>
<div style="display: none" id="e3">3</div>