How to Upload Image in ASP.net

Following code can be use to upload employee image and saving at server....

protected void btn_upload_Click(object sender, EventArgs e)
    {
        imageflag = 1;

        if (!FileUpload_image.HasFile)
        {
            Alert.Show("No file for uploading");
            return;
        }
        if (FileUpload_image.HasFile)
        {
            //string imagetype = FileUpload_image.PostedFile.ContentType;
            string[] acceptedTypes = new string[] 
            { 
                "image/bmp", 
                "image/jpeg", 
                "image/tiff", 
                "image/gif", 
                "image/png" 
                     };

            if (!acceptedTypes.Contains(FileUpload_image.PostedFile.ContentType))
            {
                Alert.Show("This is not image file");
                return;
            }
            Bitmap image = ResizeImage(FileUpload_image.PostedFile.InputStream, 84, 118);
            string imagename = Guid.NewGuid().ToString();
            image.Save(Server.MapPath("~/Employee Pictures/") + imagename + ".jpg", System.Drawing.Imaging.ImageFormat.Jpeg);
            Img_Employee.ImageUrl = "~/Employee Pictures/" + imagename + ".jpg";
            image_path = "~/Employee Pictures/" + imagename + ".jpg";
        }


    }
    private Bitmap ResizeImage(Stream streamImage, int maxWidth, int maxHeight)
    {
        Bitmap originalImage = new Bitmap(streamImage);
        int newWidth = originalImage.Width;
        int newHeight = originalImage.Height;
        double aspectRatio = (double)originalImage.Width / (double)originalImage.Height;

        if (aspectRatio <= 1 && originalImage.Width > maxWidth)
        {
            newWidth = maxWidth;
            newHeight = (int)Math.Round(newWidth / aspectRatio);
        }
        else if (aspectRatio > 1 && originalImage.Height > maxHeight)
        {
            newHeight = maxHeight;
            newWidth = (int)Math.Round(newHeight * aspectRatio);
        }

        return new Bitmap(originalImage, newWidth, newHeight);
    }