Images not saving to the folder on the webserver but saving in localhost

if (FileUploadSignature.HasFile)
        {
            string ImgExt = System.IO.Path.GetExtension(FileUploadSignature.PostedFile.FileName).ToUpper();
            if (ImgExt == ".PNG" || ImgExt == ".BMP" || ImgExt == ".GIF" || ImgExt == ".JPG" || ImgExt == ".JPEG")
            {
                if (System.IO.File.Exists(Server.MapPath(@"~\Signature\" + txtEmployeeID.Value.Trim() + ".Jpeg")))
                {
                    System.IO.File.Delete(Server.MapPath(@"~\Signature\" + txtEmployeeID.Value.Trim() + ".Jpeg"));
                }

                System.Drawing.Image image = System.Drawing.Image.FromFile(FileUploadSignature.PostedFile.FileName);
                int thumbWidth = image.Width;
                if (thumbWidth > 100)
                {
                    thumbWidth = 100;
                }
                else
                {
                    thumbWidth = image.Width;
                }
                int srcWidth = image.Width;
                int srcHeight = image.Height;
                Decimal sizeRatio = ((Decimal)srcHeight / srcWidth);
                int thumbHeight = Decimal.ToInt32(sizeRatio * thumbWidth);
                Bitmap bmp = new Bitmap(thumbWidth, thumbHeight);
                System.Drawing.Graphics gr = System.Drawing.Graphics.FromImage(bmp);
                gr.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
                gr.CompositingQuality = System.Drawing.Drawing2D.CompositingQuality.HighQuality;
                gr.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;
                System.Drawing.Rectangle rectDestination = new System.Drawing.Rectangle(0, 0, thumbWidth, thumbHeight);
                gr.DrawImage(image, rectDestination, 0, 0, srcWidth, srcHeight, GraphicsUnit.Pixel);
                bmp.Save(Server.MapPath(@"~\Signature\"+txtEmployeeID.Value.Trim()+".Jpeg"), System.Drawing.Imaging.ImageFormat.Jpeg);
                bmp.Dispose();
                ShowMessage("Saved Sucessfully");
            }
            else
            {
                ShowMessage("Invalid Picture Format/Type");
                return;
            }
        }
        else
        {
            ShowMessage("Please select the image then click save");
            return;
        }