Need help: Merge pdf files

Hi gurus,

I have a gridview containing rows for my blob data types (pdf files). My gridview has a checkboxes for selecting rows and I am able to retrieve/open pdf files for selecting one row only. What I want is to select multiple rows and merge all the pdf files into one. How can I do that?, I am using C# and PDFSplitMerge ActiveX object for merging pdfs. Also, any source tutorials for PDFSplitMerge ActiveX object?