программный код на Бэйсике, проверьте его на ошибки

[sevych]

Задали написать программный код на Бэйсике, проверьте его на ошибки если вам не трудно.

Imports System.Math
Public Class Form1
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles
MyBase.Load

End Sub
Sub vivod(ByVal Z As Double, ByVal T As TextBox)
T.Text = CStr(Z)
End Sub
Sub Proc(ByVal x As Double, ByRef f As Double)
Dim f1, f2, f3 As Double

If -3 <= x <= 1 Then
f1 = Exp(-2 * x)
f2 = 1 + x
f3 = Sqrt(Abs(x))
f = Cos(x) ^ 4
If f < f1 Then
f = f1
End If
If f < f2 Then
f = f2
End If
If f3 < f Then
f = f3
End If
ElseIf x > 3 Then
f = 3 * Log(x ^ 3)
Else
f = Log10(x) ^ 3
End If

End Sub


Public Sub proc1(ByVal a As Double, ByVal b As Double, ByVal h As Double)
Dim i As Integer, n As Integer, f As Double, x As Double, fmax As Double
n = CInt(Fix((b - a) / h) + 1)
fmax = Double.MinValue
For i = 1 To n
x = a + (i - 1) * h
Proc(x, f)
If f > fmax Then
fmax = f
End If
vivod(fmax, Textbox1)
Next
End Sub

Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim a As Double, b As Double, h As Double
a = -5
b = 5
h = 0.025
proc1(a, b, h)
End Sub
End Class