Hi,
 I have created an application with C# .net and powerpoint2007 (vsto addin),  i am using code 
Presntation.SlideMaster.Background.Fill.UserPicture(PictureFileName); 
 to set background of SlideMaster, but its apply only the first  SlideMaster in a presentation. when i create 2 or more SlideMaster in a  single presentation , i need to select the current SlideMaster and apply  the picture as background.How can i locate selected SlideMaster from a  presenation and set background using c# code..
 Pls help me.