How to resize the image by passing the parameter of width and height of image

public System.Drawing.Image resizeImage(int nWidth, int nHeight, string photoPath)
        {
            System.Drawing.Image imgPhoto = System.Drawing.Image.FromFile(photoPath);
            int sourceWidth = imgPhoto.Width;
            int sourceHeight = imgPhoto.Height;
            if (sourceWidth < sourceHeight)
            {
                int buff = nWidth;
                nWidth = nHeight;
                nHeight = buff;
            }
            int sourceX = 0, sourceY = 0, destX = 0, destY = 0;
            float nPercent = 0, nPercentW = 0, nPercentH = 0;
            nPercentW = ((float)nWidth / (float)sourceWidth);
            nPercentH = ((float)nHeight / (float)sourceHeight);
            if (nPercentH < nPercentW)
            {
                nPercent = nPercentH;
                destX = System.Convert.ToInt16((nWidth -
                          (sourceWidth * nPercent)) / 2);
            }
            else
            {
                nPercent = nPercentW;
                destY = System.Convert.ToInt16((nHeight -
                          (sourceHeight * nPercent)) / 2);
            }
            int destWidth = (int)(sourceWidth * nPercent);
            int destHeight = (int)(sourceHeight * nPercent);
            Bitmap bmPhoto = new Bitmap(nWidth, nHeight,
                       PixelFormat.Format24bppRgb);
            bmPhoto.SetResolution(imgPhoto.HorizontalResolution,
                         imgPhoto.VerticalResolution);
            Graphics grPhoto = Graphics.FromImage(bmPhoto);
            grPhoto.Clear(Color.White);
            grPhoto.InterpolationMode =
                System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
            grPhoto.DrawImage(imgPhoto,
                new Rectangle(destX, destY, destWidth, destHeight),
                new Rectangle(sourceX, sourceY, sourceWidth, sourceHeight),
                GraphicsUnit.Pixel);
            grPhoto.Dispose();
            imgPhoto.Dispose();
            return bmPhoto;
        }