This must be a very simple problem for JS experts, but I don't know enough yet about JS to know how to solve it.

After successfully adding and using jQuery's form validator, I'd like to add a simple "Please computer a+b" anti-SPAM check.

The problem is how to combine the two?

Here's a simplified example:
	<script src="http://code.jquery.com/jquery.min.js"></script>
	<script type="text/javascript" src="js/jquery.validate.js"></script>
	<script type="text/javascript">
		//========= jQuery form validator
		jQuery.extend(jQuery.validator.messages, {
		    required: "This field is required.",
		    email: "Please enter a valid e-mail address."

		//========= Simple, anti-spam scheme  
		var a = Math.ceil(Math.random() * 10);
		var b = Math.ceil(Math.random() * 10);       
		var c = a + b
		function DrawBotBoot()
		    document.write("Compute "+ a + " + " + b +"? ");
		    document.write("<input id='BotBootInput' type='text' maxlength='2' size='2'/>");
		function ValidBotBoot(){
		    var d = document.getElementById('BotBootInput').value;
		    if (d == c) return true;
		    return false;
		//========= ?How to check anti-spam answer + validate other fields in form?
		  	/*submitHandler: function(form) {


<form action="send.php" method="post" id="myform">
	Name <input type="text" maxlength="25" id="name" name="name" class="required"/>
	Anti-SPAM check<script type="text/javascript">DrawBotBoot()</script>

	<input type="submit" class="submit" value="Send" onclick="alert(ValidBotBoot());"/>

Thanks for any help.