Option Explicit
Private Declare Function GetSystemMetrics Lib "user32.dll" (ByVal nIndex As Long) As Long
Const SM_CXSCREEN = 0
Const SM_CYSCREEN = 1
Sub Tst()
Dim x As Long, y As Long
x = GetSystemMetrics(SM_CXSCREEN)
y = GetSystemMetrics(SM_CYSCREEN)
....
End Sub