Beginner here, Code proofreader needed/wanted

[Belitaross]

Hi, I think I might be doing something wrong. I am using Visual Web Developer 2010. I am trying to get a error message to pop up but the program keeps saying that 'Show is not a member of Messagebox' and I really don't know what to do. Here is the code below. I would really like if someone could point me in the right direction, please. Then error message code is at the bottom, Thanks.

<code>

    Dim decAddCharges As Decimal                'Additional Charges
    Dim decSubtotal As Decimal                  'Subtotal
    Dim decTax As Decimal                       'Tax
    Dim decTotal As Decimal                     'Total of all charges
    Const decTAX_RATE As Decimal = 0.08D        'Tax Rate. Consts CANNOT be changed by a programming statment

    Try
        'Calculate and display the room charges.
        decRoomCharges = CDec(txtNights.Text) *
                         CDec(txtNightlyCharge.Text)    '<---Calculating(mulitplying) the room charges
        lblRoomCharges.Text = decRoomCharges.ToString("c")  '<---Displaying decRoomCharges in lblRoomCharges

        'Calucalt and display the additional charges.
        decAddCharges = CDec(txtRoomService.Text) +
                        CDec(txtTelephone.Text) +
                        CDec(txtMisc.Text)              '<---Calculating(adding) the Additional charges
        lblAddCharges.Text = decAddCharges.ToString("c")    '<---Displayig decAdditionalCharges(decAddCharges
        'in lblAddCharges.

        'Calculate and display the subtotal.
        decSubtotal = decRoomCharges + decAddCharges '<---Calculating the Subtotal
        lblSubtotal.Text = decSubtotal.ToString("c")  '<---Displaying decSubtotal in lblSubtotal

        'Calculate and display the tax.
        decTax = decSubtotal * decTAX_RATE '<---Calculating(multiplying) the Tax
        lblTax.Text = decTax.ToString("c")  '<---Displaying decTax in lblTax

        'Calculate and display the total charges.
        decTotal = decSubtotal + decTax     '<---Calculating(adding) the Total Charges
        lblTotal.Text = decTotal.ToString("c")  '<---Displaying decTotal in lblTotal.

        'Change and display the total charges.
        lblTotal.BackColor = Drawing.Color.Blue
        lblTotal.ForeColor = Drawing.Color.White

    **Catch ex As Exception
        'Error message
        MessageBox.Show("All input must be vaild numberic values.")**
    End Try

</code>