Click An Anchor To Submit A Form But It Fails?

I am missing something *super simple* it seems: I have a <form...> like so:

HTML Code:

<form id="fromPreview2commitForm" action="[thisurl]" method="post">

..on a page with JS like so:

Code:

function userBackingOutFromPreviewing() {
document.forms["fromPreview2commitForm"].submit();
}

and an anchor like so:

HTML Code:

<a href="javascript:void(0);" onClick="userBackingOutFromPreviewing()">here</a>

but I am getting this error in FF3/Mac: document.forms.fromPreview2commitForm.submit is not a function Why?I just want the anchor (when ciicked) to submit the form.I have been over several examples I found while googling.. and I follow them.. but still getting this error.