Hi Tao,
The FindWindow function is declared as follows:
DECLARE INTEGER FindWindow IN user32;
STRING lpClassName, STRING lpWindowName
If you are not sure about window's class set it to Null, e.g.
hWindow = FindWindow(Null, 'Calculator')
If succeedes the FindWindow returns a handle to the window, otherwise it returns zero.
* * *
Check code samples with FindWindow function:
Activating Windows Calculator
http://www.news2news.com/vfp/?example=26Scanning a hierarchy of child windows down from the main VFP window
http://www.news2news.com/vfp/?example=261
