Help with this Code?

I am trying to replace the text, FILENAME, which is in RichTextBox1 with whatever the person types in TextBox15. Any help?

vb Code:

Public Class Form1
 
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        If RichTextBox1.Contains("FILENAME") Then Replace("FILENAME", TextBox15.Text)
        RichTextBox1.Text = RichTextBox1.Text.Replace("""", "\""")
    End Sub

Maybe try replacing it with this...

Code:

---

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        If RichTextBox1.Contains("FILENAME") Then
            RichTextBox1.Text = (TextBox15.Text)
            RichTextBox1.Text = RichTextBox1.Text.Replace("""", "\""")
        End If
    End Sub

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