Disable Signature Pad

[wgalliance]

I have used the Caspio tutorial for adding a digital signature (http://forums.caspio.com/index.php?/topic/4693-js-adding-a-digital-signature-to-a-submission-form/). The signature is working great, but I want a way to disable it if the user has already "signed" their submission. I can use rules to hide the signature portion, but I cannot submit the page without the user submitting a new signature.

This is the code for the signature capture:

<canvas class="pad" width="218" height="55" style="margin: 0px 0px 0px 100px;  border-style: solid; border-width: 1px; border-color: #bbbbbb #dbdfe6 #e3e9ef #e2e3ea; -webkit-border-radius: 1px; -moz-border-radius: 1px; -o-border-radius: 1px; border-radius: 1px; -webkit-box-sizing: border-box; -moz-box-sizing: border-box; box-sizing: border-box; background-color: #FFFFFF;"></canvas></br>
<span style="margin: 0px 0px 0px 264px;"><input type="reset" class="clearButton" value="Clear"></span>
<input type="hidden" name="output" class="output">
<script type="text/javascript">
$(document).ready(function () {
  $('#caspioform').signaturePad({drawOnly : true});
});
$("#cb_sign_wrapper form").submit(function(){
$("#InsertRecordSignature")[0].value = $("#cb_sign_wrapper .output")[0].value;
});
</script>

I want to disable the signature if the field has already been completed. Has anyone done this already and could provide the code?

[roattw]

Bump?