mail attachment

hello, i would to attach file to my mail, and the file path to my mail is on a textbox. I would like to  know how i can tell it, that the file to be attached is the text on the textbox.
Imports System.Net
Imports System.Net.Mail

Dim loginInfo As New NetworkCredential("yourUserName@gmail.com", "yourGMailPassword")
Dim msg As New MailMessage(EmailFromTextBox.Text, EmailToTextBox.Text, EmailSubjectTextBox.Text, EmailBodyTextBox.Text)
msg.IsBodyHtml = True
StatusLabel.Visible = False

Try
    Dim client As New SmtpClient("smtp.gmail.com", 587)
    client.EnableSsl = True
    client.UseDefaultCredentials = false
    client.Credentials = loginInfo
    client.Send(msg)
Catch ex As SmtpException
    StatusLabel.Vis ...