代码如下：

Dim Count As Integer
Count = Registry.GetValue("HKEY_CURRENT_USER\\Software\\MyApp","Count",0)
Registry.SetValue("HKEY_CURRENT_USER\\Software\\MyApp","Count",Count + 1)

Dim n As Integer = GetConfigValue("Count",1)
Dim Code As String = GetConfigValue("Register" & ComputerId,"")
Dim Ok As Boolean
If Code > "" AndAlso DecryptText(Code,"abc","abc") = ComputerId Then \'如果注册码正确
    OK = True
Else
    If n > 30 Then
        Forms("注册").Open()
        Code = GetConfigValue("Register" & ComputerId,"")
        If Code > "" AndAlso DecryptText(Code,"abc","abc") = ComputerId Then \'如果注册码正确
            OK = True
        End If
    End If
    If n > 60 AndAlso Ok = False Then
        Messagebox.Show("您正在使用的产品已经超出试用次数!")
        Syscmd.Project.Exit()
    End If
End If
n = n + 1
SaveConfigValue("Count",n)