How to update the xml element using c#

How to update the xml element using c#

I have xml file with photo and user tag. Now I have my website with browse
the image from local pc and upload into web application img folder, after
successfully uploading image, it should be show in the website by
refreshing website. But the issue is that the xml tag for new browse image
is not generating so website is not show the uploaded images in the
website.
Below is the code behind.
protected void Page_Load(object sender, EventArgs e) {
}
protected void btnSubmit_Click(object sender, EventArgs e)
{
// Before attempting to save the file, verify
// that the FileUpload control contains a file.
if (FileUpload1.HasFile)
{
// Call a helper method routine to save the file.
SaveFile(FileUpload1.PostedFile);
XmlDocument doc = new XmlDocument();
//string path = @"C:\Users\khant\Documents\visual studio
2012\Projects\UploadImageRetrieve\UploadImageRetrieve\photos.xml";
doc.Load("C:\\Users\\khant\\Documents\\visual studio
2012\\Projects\\UploadImageRetrieve\\UploadImageRetrieve\\photos.xml");
string filenm = FileUpload1.FileName;
XmlElement user = doc.CreateElement("user");
XmlElement photo = doc.CreateElement("photo");
XmlText phototext = doc.CreateTextNode("img/"+filenm);
//doc.SelectSingleNode("/appSettings/add").Attributes["value"].Value
= "hello";
//doc.SelectNodes("/appSettings/add").Item(2).Attributes["value"].Value
= "hello";
photo.AppendChild(phototext);
user.AppendChild(photo);
doc.Save("C:\\Users\\khant\\Documents\\visual studio
2012\\Projects\\UploadImageRetrieve\\UploadImageRetrieve\\photos.xml");
}
else
// Notify the user that a file was not uploaded.
UploadStatusLabel.Text = "You did not specify a file to upload.";
}
void SaveFile(HttpPostedFile file)
{
// Specify the path to save the uploaded file to.
string savePath = "C:\\Users\\khant\\Documents\\visual studio
2012\\Projects\\UploadImageRetrieve\\UploadImageRetrieve\\img\\";
// Get the name of the file to upload.
string fileName = FileUpload1.FileName;
// Create the path and file name to check for duplicates.
string pathToCheck = savePath + fileName;
// Create a temporary file name to use for checking duplicates.
string tempfileName = "";
// Check to see if a file already exists with the
// same name as the file to upload.
if (System.IO.File.Exists(pathToCheck))
{
int counter = 2;
while (System.IO.File.Exists(pathToCheck))
{
// if a file with this name already exists,
// prefix the filename with a number.
tempfileName = counter.ToString() + fileName;
pathToCheck = savePath + tempfileName;
counter++;
}
fileName = tempfileName;
// Notify the user that the file name was changed.
UploadStatusLabel.Text = "A file with the same name already
exists." +
"<br />Your file was saved as " + fileName;
}
else
{
// Notify the user that the file was saved successfully.
UploadStatusLabel.Text = "Your file was uploaded successfully.";
}
// Append the name of the file to upload to the path.
savePath += fileName;
// Call the SaveAs method to save the uploaded
// file to the specified directory.
FileUpload1.SaveAs(savePath);
}
}
Please let me know where i am wrong.
Thanks.