Filling data in PDF continuation pages

//Load the PDF document 
PdfLoadedDocument page1Document = new PdfLoadedDocument("../../Data/FormPage.pdf");
 
//Load the Continuous PDF document 
PdfLoadedDocument pageContinuationDocument = new PdfLoadedDocument("../../Data/FormContinuationPage.pdf");
 
//Gets the form field collection from Loaded document
PdfLoadedFormFieldCollection form = page1Document.Form.Fields;
            
//Gets the form field collection from Continuous document
PdfLoadedFormFieldCollection formContinuation = pageContinuationDocument.Form.Fields;
 
//Sets Field as PdfLoadedTextBoxField
PdfLoadedField FirstName = null;
if (form.TryGetField("FirstName", out FirstName))
{
     (FirstName as PdfLoadedTextBoxField).Text = "Andrew";
     (FirstName as PdfLoadedTextBoxField).ReadOnly = true;
}
 
PdfLoadedField LastName = null;
if (form.TryGetField("LastName", out LastName))
{
     (LastName as PdfLoadedTextBoxField).Text = "Fuller";
     (LastName as PdfLoadedTextBoxField).ReadOnly = true;
}
 
PdfLoadedField FirstNameContinuation = null;
if (formContinuation.TryGetField("FirstName", out FirstNameContinuation))
{
     (FirstNameContinuation as PdfLoadedTextBoxField).Text = "Andrew";
     (FirstNameContinuation as PdfLoadedTextBoxField).ReadOnly = true;
}
 
PdfLoadedField LastNameContinuation = null;
if (formContinuation.TryGetField("LastName", out LastNameContinuation))
{
     (LastNameContinuation as PdfLoadedTextBoxField).Text = "Fuller";
     (LastNameContinuation as PdfLoadedTextBoxField).ReadOnly = true;
}
 
//Creates new Pdf Document
PdfDocument doc = new PdfDocument();
            
//Append the Loaded document to new document and dispose it                  
doc.Append(page1Document);
page1Document.Close();
 
doc.Append(pageContinuationDocument);
pageContinuationDocument.Close();
 
//Sets the PdfDocument Form as Read only
doc.Form.ReadOnly = true;
 
//Save the document and dispose it
doc.Save("sample.pdf");
doc.Close(true);