HTML
<div id="myDiv" style="display:none;" class="answer_list" >WELCOME</div>
<input type="button" name="answer" onclick="ShowDiv()" />
JavaScript
function ShowDiv() {
document.getElementById("myDiv").style.display = "";
}
Or if you wanted to use jQuery with a nice little animation:
<input id="myButton" type="button" name="answer" />
$('#myButton').click(function() {
$('#myDiv').toggle('slow', function() {
// Animation complete.
});
});