สอบถ้าเรื่องใช้ textbox ในการคำนวณอัตโนมัติหน่อยครับ Asp.net VB.Net

Public Sub TextBox1_TextChanged(sender As Object, e As System.EventArgs) Handles TextBox1.TextChanged
        If TextBox1.Text <> "" And TextBox2.Text <> "" Then
            TextBox3.Text = TextBox1.Text * TextBox2.Text

        End If

    End Sub

    Public Sub TextBox2_TextChanged(sender As Object, e As System.EventArgs) Handles TextBox2.TextChanged
        If TextBox1.Text <> "" And TextBox2.Text <> "" Then
            TextBox3.Text = CDbl(TextBox1.Text) + CDbl(TextBox2.Text)

        End If
    End Sub