pick object with mouse direct3d8, an example that it does't work

[albusorin]

I tried to make an example for showing how u can pick object from an direct3d enviroment, i used a part of a code from direct3d8 sdk - PICK - the function in my example is : D3DVECTOR GetMousePosition3D(POINT ptCursor){...}, but it does'n work!!! What can i do...?!?
Here is the code : http://www.geocities.com/albusorin/examples.htm
Please help...
Thanks :)