Object cannot be cast from DBNull to other types.

Question

my code is

private int GetNextStudentID()

{

command.CommandText = "SELECT IDENT_CURRENT ('admn') + IDENT_INCR ('admn')";

try

{

connection.Open();

int nextID = Convert.ToInt32(command.ExecuteScalar());// here i am getting error

return nextID;

}

catch (SqlException ex)

{

MessageBox.Show(ex.Message);

}

finally

{

connection.Close();

}

return 0;

}