<div onclick="a()">
<span onclick="b()">テスト</span>
</div>

<script language="JavaScript">
<!--
function a(){
    alert("div");
}
function b(){
    alert("span");
}
// -->
</script>

<p id="test"></p>
<script language="JavaScript">
<!--
function c(){
    // 2度押し防止
    button1.disabled = true;

    var div = document.createElement("div");
    div.id = 'div1';
    var span = document.createElement("span");

    var span = document.createElement('span');
    span.id = 'span1';
    span.innerHTML = 'テスト';

    div.appendChild(span);
    document.getElementById("test").appendChild(div);

    div1.addEventListener('click', function() {
        alert("div")
    }, false);
 
    span.addEventListener('click', function() {
        alert("span")
    }, false);
}
// -->
</script>