java - How add text over signature field using itext

Question

I am working with: itext-2.1.7 + Java 1.6 + bcmail-jdk14-1.38.jar + bcprov-jdk14-1.38.jar + bctsp-jdk14-1.38.jar The visualization of the pdf i made with DigiSigner Applet (http://www.digisigner.com/)

I use de follow function addSignatureField to create the signature fields. This function add the signature field with color style. But I need also add some kind of title or label indication with the user name of who should sign in this field. How can I add this title over the signature field and when the user sign the pdf the title should disapear?

my function to create signature fields:

public static void addSignatureField(PdfStamper stamper, int page, Rectangle rectangle, String fieldName)
    {
        //create signature field
        PdfFormField signatureField = PdfFormField.createSignature(stamper.getWriter());
        signatureField.setPage(page);
        signatureField.setWidget(rectangle, null);
        signatureField.setFieldName(fieldName);
        signatureField.setFlags(PdfAnnotation.FLAGS_PRINT);

        // border color
        signatureField.setMKBorderColor(Color.BLACK);
        // background color
        signatureField.setMKBackgroundColor(Color.WHITE);

        // add field to document
        stamper.addAnnotation(signatureField, page);
}

output image with my actual signature field in the pdf file -> screenshot of my software

Over this signature field should be a text title who say "Sign here, you John Doe!"