Clearing a Signature Field on an Invalid Document
If you would like to ensure that users do not apply Digital Signatures to incomplete forms, after the signature is applied, reset the Signature field using the "resetForm" method along with the full name of the signature field:
var doc = event.target;
doc.resetForm("XMLExampleForm[0].XMLExamplePage1[0].SignatureField1[0]");
In this example the user must enter the Name field to apply a valid signature. If the Name is removed or the Name is not entered, the signature field is cleared.