I am trying to Merge using c# this is not working :( , Its urgent Pls reply

          string sourceDoc = @"D:\XXXXX.pdf"; 

            AcroPDDoc objPDDoc = new AcroPDDoc();         

            objPDDoc.Open(sourceDoc);

            int numberpgaes = objPDDoc.GetNumPages(); //Getting Number here

            AcroPDDoc objPDDocNew = new AcroPDDoc();

            if (objPDDocNew.Create())

            {

                MessageBox.Show("New File Created");

            }

            if (objPDDocNew.InsertPages(-1, objPDDoc,0, numberpgaes, 1))

            {

                MessageBox.Show("File Inserted");

            }

            objPDDocNew.OpenAVDoc("Template");