i want to start calc.exe and hide it  

but only can start the exex but cant hide  

what error in my code??  

```
Imports System.Runtime.InteropServices
Imports System.IntPtr
Public Class Form1
    <DllImport("user32.dll", SetLastError:=True, CharSet:=CharSet.Auto)> _  
    Private Shared Function ShowWindowAsync(ByVal hwnd As IntPtr, ByVal nCmdShow As Integer) As Boolean
    End Function 
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Dim a As IntPtr = Process.GetProcessesByName("Calc")(0).Id
        ShowWindowAsync(a, 0)
    End Sub
End Class

```