Copy TextBox Content To Another using Checkbox

For this, I am using Two textboxes named txtpermanentadd and txtpresentadd and a checkbox named checkbox1. Screenshot given below.

To make textbox for typing  address, change multiline property of textbox to True.

Write the below code in the Checkedchanged event of Checkbox1

Private Sub CheckBox1_CheckedChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles CheckBox1.CheckedChanged

        If CheckBox1.Checked = True Then

            If txtPermanantadd.Text <> "" Then

                txtPresentadd.Text = txtPermanantadd.Text

            Else

                MessageBox.Show("Permanent Address field is empty")

                CheckBox1.Checked = False

                Exit Sub

            End If

        Else

            txtPresentadd.Text = ""

        End If

    End Sub

The permanentaddress is copied to presentaddress when the checkbox1 is checked, otherwise clear the content in the present address field.