Allow TextBox in Form2 to read and display ComboBox from Form1

I have to be able to display a Customer ID (listed in a ComboBox) from Form1 in a TextBox on Form2
When I run the program I get "System.Data.DataRowView" in my TextBox on Form2.

Form1

Public Shared str As String

  Public Sub CustomerIDComboBox_SelectedIndexChanged(sender As System.Object, e As System.EventArgs) Handles CustomerIDComboBox.SelectedIndexChanged
        str = Convert.ToString(CustomerIDComboBox.SelectedValue)
    End Sub
Form2
  Public Sub CustomerIDTextBox_TextChanged(sender As System.Object, e As System.EventArgs) Handles CustomerIDTextBox.TextChanged
        CustomerIDTextBox.Text = CustomerLookupForm.str
    End Sub