Just create a page and paste this code below onto it.

<h2>[page_name]</h2>

[if:message]<p>[message]</p>[endif:message]

<script type="text/javascript">
/*<![CDATA[*/
var users_online = new Array();

function setOnline() {
[start:whos_online][start:users_online]
users_online[users_online.length] = '[whos_online_username]';
[stop:users_online][stop:whos_online]
}

function getOnline(username) {
for(var i = 0; i < users_online.length; i++) {
if(users_online[i] == username) {
// User is online
return '<span style="color: #008000">Online<\/span>';
}
}

// User is not online
return '<span style="color: #F00">Offline<\/span>';
}

setOnline();

document.write('<table border="0" cellspacing="1" cellpadding="1" width="100%">');
document.write('<tr class="tableHeader">');
document.write('<td><span class="headingFont">#<\/span><\/td>');
document.write('<td><span class="headingFont">Username<\/span><\/td>');
document.write('<td><span class="headingFont">Userlevel<\/span><\/td>');
document.write('<td><span class="headingFont">Posts<\/span><\/td>');
document.write('<td><span class="headingFont">Status<\/span><\/td>');
document.write('<\/tr>');

[start:members]
if ("[userlevel]" == "God Admin") {
document.write('<tr class="[alt_color]">');
document.write('<td>[increment]<\/td>');
document.write('<td><a href="[member_url]">[username]<\/a><\/td>');
document.write('<td>[userlevel]<\/td>');
document.write('<td>[posts]<\/td>');
document.write('<td>');
document.write(getOnline('[username]'));
document.write('<\/td>');
document.write('<\/tr>');
}
if ("[userlevel]" == "Administrator") {
document.write('<tr class="[alt_color]">');
document.write('<td>[increment]<\/td>');
document.write('<td><a href="[member_url]">[username]<\/a><\/td>');
document.write('<td>[userlevel]<\/td>');
document.write('<td>[posts]<\/td>');
document.write('<td>');
document.write(getOnline('[username]'));
document.write('<\/td>');
document.write('<\/tr>');
}
if ("[userlevel]" == "Moderator") {
document.write('<tr class="[alt_color]">');
document.write('<td>[increment]<\/td>');
document.write('<td><a href="[member_url]">[username]<\/a><\/td>');
document.write('<td>[userlevel]<\/td>');
document.write('<td>[posts]<\/td>');
document.write('<td>');
document.write(getOnline('[username]'));
document.write('<\/td>');
document.write('<\/tr>');
}
[stop:members]
document.write('<\/table>');
/*]]>*/
</script>