getting text into contentpage from textbox which is in masterpage in asp.net using c#

[crazy.works]

i have a master page with a textbox of multiline, a button and a contentplace holder.while the master page loading i added text from the content file into the textbox.the user can change the text in the textbox and when user click the button the text in the text box has to replace the original content in the same content file.my code in masterpage cs file is\[code\] FileInfo fil = new FileInfo("c:/documents and settings/administrator/my documents/visual studio 2010/Projects/WebApplication1/WebApplication1/contentpage.aspx"); protected void Page_Load(object sender, EventArgs e) { contenttext.Text = File.ReadAllText(fil.ToString()); } protected void Click(object sender, EventArgs e) { Response.Redirect("contentpage.aspx"); }\[/code\]and in content page