为什么调用存储过程会出现这样的结果?

[WebMethod(EnableSession=false)]
public int AddBooking(int flightID,string passengerID,int travelClassID)
{ 
 SqlConnection sqlConnection;
 SqlCommand sqlCommand;
 SqlDataAdapter sqlDataAdapter;
 DataSet dataSet;
 sqlConnection=new SqlConnection("data source=minth-190;initial catalog=AirlineServiceProvider;password=sa;persist security info=True;user id=sa;workstation id=MINTH-100;packet size=4096");
 try
   { 
    sqlConnection.Open();    sqlCommand=new SqlCommand("AddBooking");
    sqlCommand.CommandType=CommandType.StoredProcedure;
    //加入这两句
    SqlParameter paramfilghtID=new SqlParameter("@iFlight",SqlDbType.Int);
    paramfilghtID.Value=flightID;
    sqlCommand.Parameters.Add(paramfilghtID);
   SqlParameter paramPassengerID=new SqlParameter"@sPassengerID",SqlDbType.VarChar,20);
paramPassengerID.Value=passengerID;
sqlCommand.Parameters.Add(paramPassengerID);
SqlParameter paramTravelClassID=new SqlParameter("@iTravelClassID",SqlDbType.Int);
paramTravelClassID.Value=travelClassID;
sqlCommand.Parameters.Add(paramTravelClassID);
SqlParameter paramBookingID=new SqlParameter("@iBooingID",SqlDbType.Int);
paramBookingID.Direction=ParameterDirection.Output;
sqlCommand.Parameters.Add(paramBookingID);
qlCommand.ExecuteNonQuery();
int bookingID=Convert.ToInt32(sqlCommand.Parameters["@iBooingID"].Value);
return bookingID;
}
catch(Exception exx)
{
throw exx;
}
finally
{
if(sqlConnection.State==ConnectionState.Open)
{
sqlConnection.Close();
}}}