In a C# application using SQL Server 2005, how to resolve the error during an INSERT "[IndexOutOfRangeException: Index was outside the bounds of the array.]?

I am developing a C# ASP.Net application and once my program executes, it stops
executing at:

command.Parameters.Add("@office", SqlDbType.VarChar).Value = rowtoappend[1];
The error message states:

[IndexOutOfRangeException: Index was outside the bounds of the array.]

How would you resolve this error?

The value of rowtoappend[1] is "" 

 public void AppendManualWSRows(string[] rowtoappend)
        {
            using (SqlConnection conn = new SqlConnection(connString))
            {
                SqlCommand command = new SqlCommand("proc_SMR_XLS_Manual_Insert", conn);
                command.CommandType = CommandType.StoredProcedure;
                command.Parameters.Add("@bank", SqlDbType.VarChar).Value = rowtoappend[0];
                command.Parameters.Add("@office", SqlDbType.VarChar).Value = rowtoappend[1];
                command.Parameters.Add("@checknum", SqlDbType.VarChar).Value = rowtoappend[2];
                conn.Open();
                command.ExecuteNonQuery();
                conn.Close();
            }

        }I am developing a C# ASP.Net application and once my program executes, it stops
executing at:

command.Parameters.Add("@office", SqlDbType.VarChar).Value = rowtoappend[1];


[IndexOutOfRangeException: Index was outside the bounds of the array.]

How would you resolve this error?

The value of rowtoappend[1] is "" 

 public void AppendManualWSRows(string[] rowtoappend)
        {
            using (SqlConnection conn = new SqlConnection(connString))
            {
                SqlCommand command = new SqlCommand("proc_SMR_XLS_Manual_Insert", conn);
                command.CommandType = CommandType.StoredProcedure;
                command.Parameters.Add("@bank", SqlDbType.VarChar).Value = rowtoappend[0];
                command.Parameters.Add("@office", SqlDbType.VarChar).Value = rowtoappend[1];
                command.Parameters.Add("@checknum", SqlDbType.VarChar).Value = rowtoappend[2];
                conn.Open();
                command.ExecuteNonQuery();
                conn.Close();
            }

        }