Please help about sqlparameter

i am using sql parameters for authenticat login and password but the porble is here an error ocurs "Specific casting not valid"
see the code


public bool Authenticate(string user, string pass)
{
bool authenticated = false;

SqlConnection myconnection = new SqlConnection();
myconnection.ConnectionString = "Persist Security Info=False;User Id = pcms;Password = pcms;Database=ImportPCMS;Data Source = Vilas;";
myconnection.Open();
SqlCommand cmd = new SqlCommand("Select Username,Password from muser",myconnection);

try
{

SqlParameter myUser = new SqlParameter("@Username",SqlDbType.VarChar, 15);
myUser.Value = user.Trim();
cmd.Parameters.Add(myUser);

SqlParameter myPassword = new SqlParameter("@Password",SqlDbType.VarChar, 15);
myPassword.Value = pass.Trim();
cmd.Parameters.Add(myPassword);

SqlParameter IsValid = new SqlParameter("@IsValid",SqlDbType.Int);
IsValid.Direction = ParameterDirection.Output;
cmd.Parameters.Add(IsValid);

cmd.ExecuteNonQuery();


if ((int)Isvalid.value ==1)


authenticated =true;

}

catch(Exception E)
{
Response.Write(E.Message);

}if ((int)Isvalid.value ==1) :mad:

1) Which line is giving the error?

2) What is the table schema?

The error's at

Code:

---

if ((int)Isvalid.value ==1)

---

because you can't cast directly from string to int.

Code:

---

if(System.Convert.ToInt64(IsValid.Value) == 1)

---

ya ,
but Isvalid.value returns a DBNull ?
why?
can u solve this?

ya ,
but Isvalid.value returns a DBNull ?
why?
can u solve this?

and there is no schema define for it

If you allow nulls in the DB (required=NO) then you will get a DBNull when you read it.....