Codigos de visual studio net

Hola,

Hola quiero ayuda con codigos de programacion de visual net uno de ellos es como mostrar un rtesultado por textbox en intentado y no puedo este una parte del programita

Private Sub calcular_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles calcular.Click
Dim alt As Double
Dim can As Integer
Dim anc As Double
Dim p_mat As Integer
Dim su As Double
Dim v_sub As Double
Dim met_cua As Double
Dim val_met As Integer
Dim iva As Double
Dim v_des As Double
Dim des As Double
Dim total As Double
Dim rec As Integer
Dim cal1 As Integer
su = (alt * anc)
su = su * p_mat
su = su + rec
su = su * can
v_sub = su
cal1 = alt * anc
met_cua = Val(cal1)
val_met = p_mat
iva = (Val(v_sub) * 0.12)
v_des = 0
If Val(can) > 5 And Val(can) < 10 Then
v_des = 0.1
ElseIf Val(can) > 10 And Val(can) < 15 Then
v_des = 0.15
Else
v_des = 0.2
End If
des = Val(v_sub * v_des)
total = (Val(v_sub) + Val(iva)) - Val(des)
End Sub