Cheque Scanning Implementation,Scanner

public string ProcessDocument()
        {
            string Output = string.Empty;
            int Count = 2;
            string[] strData = null;
            try
            {
                int nRet = -1;
                string strLog;
                string strTmp;
                MessageBox.Show("ProcessInit Start");

                ProcessInit(); // Initialisation 
                MessageBox.Show("SetupOptions Start");

                nRet = SetupOptions(); //Setup 

                if (nRet != MICR_ST_OK)
                {
                    strLog = "Setup Options FAILED...";
                    MessageBox.Show(strLog);
                }
                else
                {
                    strLog = "Setup Options SUCCESS...";
                     MessageBox.Show(strLog);

                    StringBuilder strResponse = new StringBuilder();
                    strResponse.Capacity = 8192; //8192;
                    int nResponseLength = 8192;//= 4096;
                    m_strDocInfo = "";
                    
                    nRet = MTMICRProcessCheck(m_strCurrentDeviceName, m_strOptions, strResponse, ref nResponseLength); // Process
                   
                  
                    if (nRet == MICR_ST_OK)
                    {
                        m_strDocInfo = strResponse.ToString();
                        Output = m_strDocInfo;

                        nRet = MTMICRGetValue(m_strDocInfo, "CommandStatus", "ReturnCode", strResponse, ref nResponseLength);
                        strTmp = strResponse.ToString();

                        #region Front Image

                        int nReti;
                        StringBuilder strResponsei = new StringBuilder();
                        strResponsei.Capacity = 4096;
                        int nResponseLengthi = 4096;
                        int nImageSize;
                        string strTmpi;
                        string strImageID;

                        nReti = MTMICRGetIndexValue(m_strDocInfo, "ImageInfo", "ImageSize", 1, strResponsei, ref nResponseLengthi);
                        strTmpi = strResponsei.ToString();
                        nImageSize = Convert.ToInt32(strTmpi);

                        if (nImageSize > 0)
                        {
                            nReti = MTMICRGetIndexValue(m_strDocInfo, "ImageInfo", "ImageURL", 1, strResponsei, ref nResponseLengthi);
                            strImageID = strResponsei.ToString();
                            strLog = "Image size =" + nImageSize + "ImageID = " + strImageID;


                            //MessageBox.Show(strLog);
                            byte[] imageBuf = new byte[nImageSize];
                            nRet = MTMICRGetImage(m_strCurrentDeviceName, strImageID, imageBuf, ref nImageSize);
                            if (nRet == MICR_ST_OK)
                            {
                                System.IO.FileStream fileWriter = new System.IO.FileStream(@"c:\test.jpg", System.IO.FileMode.Create);
                                fileWriter.Write(imageBuf, 0, imageBuf.Length);
                                image_Buf = imageBuf;
                                fileWriter.Close();
                                int nActualSize = nImageSize;
                                string strImageFile = g_strAppPath + "\\docimage" + ++nTotalDocProcessed + ".jpg";
                                int hFile = -1;
                                hFile = CreateFile(strImageFile, GENERIC_READ | GENERIC_WRITE,
                                      FILE_SHARE_READ | FILE_SHARE_WRITE, 0, OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL, 0);
                                if (hFile > 0)
                                {
                                    strLog = "NumOfBytes to write =" + nActualSize;

                                    //MessageBox.Show(strLog);
                                    IntPtr pOverlapped = IntPtr.Zero;
                                    bool bRet = WriteFile(hFile, imageBuf, nImageSize, ref nActualSize, pOverlapped);
                                }
                            }
                        }

                        #endregion

                        #region Back Image

                        int nRetb;
                        StringBuilder strResponseb = new StringBuilder();
                        strResponseb.Capacity = 4096;
                        int nResponseLengthb = 4096;
                        int nImageSizeb;
                        string strTmpb;
                        string strImageIDb;

                        nRetb = MTMICRGetIndexValue(m_strDocInfo, "ImageInfo", "ImageSize", 2, strResponseb, ref nResponseLengthb);
                        strTmpb = strResponseb.ToString();
                        nImageSizeb = Convert.ToInt32(strTmpb);

                        if (nImageSizeb > 0)
                        {

                            nRetb = MTMICRGetIndexValue(m_strDocInfo, "ImageInfo", "ImageURL", 2, strResponseb, ref nResponseLengthb);
                            strImageIDb = strResponseb.ToString();
                            strLog = "B Image size =" + nImageSizeb + "B ImageID = " + strImageIDb;
                            // MessageBox.Show(strLog);
                            byte[] imageBuf = new byte[nImageSizeb];
                            nRet = MTMICRGetImage(m_strCurrentDeviceName, strImageIDb, imageBuf, ref nImageSizeb);
                            if (nRet == MICR_ST_OK)
                            {
                                System.IO.FileStream fileWriter = new System.IO.FileStream(@"c:\test_b.jpg", System.IO.FileMode.Create);
                                fileWriter.Write(imageBuf, 0, imageBuf.Length);
                                image_Buf_B = imageBuf;
                                fileWriter.Close();

                                int nActualSize = nImageSizeb;
                                string strImageFile = g_strAppPath + "\\docimage" + ++nTotalDocProcessed + ".jpg";
                                int hFile = -1;
                                hFile = CreateFile(strImageFile, GENERIC_READ | GENERIC_WRITE,
                                      FILE_SHARE_READ | FILE_SHARE_WRITE, 0, OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL, 0);
                                if (hFile > 0)
                                {
                                    strLog = "B NumOfBytes to write =" + nActualSize;
                                    //  MessageBox.Show(strLog);
                                    IntPtr pOverlapped = IntPtr.Zero;
                                    bool bRet = WriteFile(hFile, imageBuf, nImageSizeb, ref nActualSize, pOverlapped);
                                }
                            }
                        }

                        #endregion

                    }
                    else
                    {
                        strLog = "MTMICRProcessCheck return code " + Convert.ToString(nRet);
                        MessageBox.Show(strLog);
                        //PrintStatus(strLog);

                    
                    }
                }
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message + " Line Number " + ex.StackTrace);
              
            }
            finally
            {
                if (m_bDeviceOpened)
                    CloseCurrentDevice();
            }
            return Output;
        }