ADO.NET :: How To Read And Bind Xml Data Into Textbox And Also Save It

how to read xml file and bind data to textbox here is my code to bind xml data to Gridview now on my gridview i have edit button

string filePath = Server.MapPath("~/feed.xml");
FeedDataSet = new DataSet();
FeedDataSet.ReadXml(filePath);
if (FeedDataSet.Tables[0].Rows.Count > 0)
{
GridView1.DataSource = FeedDataSet.Tables[0].DefaultView;
GridView1.DataBind();
}

example

name id edit
xyz 1 changename

now if i click on changename link . it pass id and edit option to same page as
xyz.com?id=1&action=edit

now how i can fill the text box using this id and if i change name and say save button then how u can save that file to xml