You can add an event handler in the HTML definition of the element like this,

<script type="text/javascript"><!--

function hitme() {

alert("I've been hit!");

}

// -->

</script>

<input type="button" id="hitme" name="hitme" value="hit me" onclick="hitme()"

Or, interestingly enough you can just assign the event's name on the object directly with a reference to the method you want to assign.

<input type="button" id="hitme2" name="hitme2" value="hit me2"/>

<script type="text/javascript"><!--

function hitme2() {

alert("I've been hit too!");

}

document.getElementById("hitme2").onclick = hitme2;

// -->

</script>

You can also use an anonymous method like this:

document.getElementById("hitme3").onclick = function () { alert("howdy!"); }

You can also use the the W3C addEvventListener() method, but it does not work in IE yet:

<input type="button" id="hitme4" name="hitme4" value="hit me4"/>

<script type="text/javascript"><!--

function hitme4() {

alert("I've been hit four!");

}