Getting ClassName of a program

There is probably an easy answer to this, but how would I go about finding the classname of a program?

Of a program, or a window? Here's for a window...

VB Code:

Private Declare Function GetClassName Lib "user32" Alias "GetClassNameA" (ByVal hwnd As Long, _
                                                                          ByVal lpClassName As String, _
                                                                          ByVal nMaxCount As Long) _
                                                                          As Long
 
Private Sub Command1_Click()
Dim s As String
 
    s = Space$(255)
    Call GetClassName(hwnd, s, Len(s))
 
    MsgBox s
    
End Sub

Thank you for the suggestion, but i figured out i can just use spy++

Justin