Public Class Form1
 
    Private mRTFInhalt1 As String
 
    Public Property RTFInhalt1 As String
        Get
            Return mRTFInhalt1
        End Get
        Set(value As String)
            mRTFInhalt1 = value
            RichTextBox1.Text = mRTFInhalt1
        End Set
    End Property
 
    Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) _
      Handles Button1.Click
        Dim frmForm2 As New Form2
 
        With frmForm2
            .RTFInhalt2 = RichTextBox1.Text
            .Frm1 = Me
            .ShowDialog()
        End With
    End Sub
End Class

Public Class Form2
 
    Private mRTFInhalt2 As String
    Private mFrm1 As Form
 
    Public Property RTFInhalt2 As String
        Get
            Return mRTFInhalt2
        End Get
        Set(value As String)
            mRTFInhalt2 = value
        End Set
    End Property
 
    Public Property Frm1 As Form1
        Get
            Return mFrm1
        End Get
        Set(value As Form1)
            mFrm1 = value
        End Set
    End Property
 
    Private Sub RichTextBox2_TextChanged(sender As System.Object, e As _
      System.EventArgs) Handles RichTextBox2.TextChanged
 
        Dim frm1 As Form1 = mFrm1
        frm1.RTFInhalt1 = RichTextBox2.Text
 
    End Sub
 
    Private Sub Form2_Load(sender As System.Object, e As System.EventArgs) _
      Handles MyBase.Load
 
        RichTextBox2.Text = mRTFInhalt2
 
    End Sub
End Class

EALA FREYA FRESENA