Error in creating stored procedure

Hi,

I want to write a stored procedure for login

a user can use either the mobileno or email as username.

a pssword field also there i want to write a stored procedure for that

below is the code for login .how to write stored procedure

SqlCommand cmdmob = new SqlCommand("select * from registration where mobile=@mobile ", con);
cmdmob.Parameters.AddWithValue("@mobile", txtuname.Text);
DataTable dtmob = new DataTable();
SqlDataAdapter damob = new SqlDataAdapter(cmdmob);
damob.Fill(dtmob);
if (dtmob.Rows.Count > 0)
{
string mobile = dtmob.Rows[0]["mobile"].ToString();
string pword = dtmob.Rows[0]["pword"].ToString();
bool flagmob = Helper.VerifyHash(txtpword.Text, "SHA512", pword);
if (mobile == txtuname.Text && flagmob == true)
{
lbltext.Text = "Success";
}
}
else
{

SqlCommand cmdmail = new SqlCommand("select * from registration where email=@email ", con);
cmdmail.Parameters.AddWithValue("@email", txtuname.Text);
DataTable dtmail = new DataTable();
SqlDataAdapter damail = new SqlDataAdapter(cmdmail);
damail.Fill(dtmail);
string email = dtmail.Rows[0]["email"].ToString();
string pwordmail = dtmail.Rows[0]["pword"].ToString();
bool flagmail = Helper.VerifyHash(txtpword.Text, "SHA512", pwordmail);
if (email == txtuname.Text && flagmail == true)
{
lbltext.Text = "Success";
Response.Redirect("~/admin/Welcome.aspx");
}
}