My web page gets expired

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C#

C#4.0

protected void btnUpload_Click(object sender, EventArgs e)
{
using (BinaryReader br = new BinaryReader(FileUpload1.PostedFile.InputStream))
{
byte[] bytes = br.ReadBytes((int)FileUpload1.PostedFile.InputStream.Length);
string strConnString = ConfigurationManager.ConnectionStrings["Crime"].ConnectionString;
using (SqlConnection con = new SqlConnection(strConnString))
{
using (SqlCommand cmd = new SqlCommand())
{
cmd.CommandText = "insert into tblFiles(Name, ContentType, Data) values (@Name, @ContentType, @Data)";
cmd.Parameters.AddWithValue("@Names", Path.GetFileName(FileUpload1.PostedFile.FileName));
cmd.Parameters.AddWithValue("@ContentType", "video/mp4");
cmd.Parameters.AddWithValue("@Data", bytes);
cmd.Connection = con;
con.Open();
cmd.ExecuteNonQuery();
con.Close();
}
}
}
Response.Redirect(Request.Url.AbsoluteUri);
}

I have problem in my above code when try to upload vedio through this code my web page gets expired I don't understand why it's happening please help ........