How do I make a "div" button submit the form its sitting in?

Are you aware of <button> elements? <button> elements can be styled just like <div> elements and can have type="submit" so they submit the form without javascript:

<form action="whatever.html" method="post">  
    <button name="mysubmitbutton" id="mysubmitbutton" type="submit" class="customButton">  
    Button Text
    </button>  
</form>  

Using a <button> is also more semantic, whereas <div> is very generic. You get the following benefits for free:

• JavaScript is not necessary to submit the form
• Accessibility tools, e.g. screen readers, will (correctly) treat it as a button and not part of the normal text flow
• <button type="submit"> becomes a "default" button, which means the return key will automatically submit the form. You can't do this with a <div>, you'd have to add a separate keydown handler to the <form> element.

There's one (non-) caveat: a <button> can only have phrasing content, though it's unlikely anyone would need any other type of content when using the element to submit a form.

onClick="javascript:this.form.submit();">

this in div onclick don't have attribute form, you may try this.parentNode.submit() or document.forms[0].submit() will do

Also, onClick, should be onclick, some browsers don't work with onClick