AVR-Chat

I am trying to change the address on my SRF08s. I have confirmed they
work ie I did a ping on each of them with the default address. In order
to change the address I need to send A0, AA, A5 and then the desired
address. This I put into cmd before calling the routines. 

I called the following routine.  I do not think I have the TWI calls
right. It returned invalid address.

int8_t srf08_ChangeAddress(uint8_t device, uint8_t Newdevice)
{
  uint8_t cmd;
  uint8_t addr;

  /* start condition */
  if (i2c_start(0x08, 1))
    return -1;

  /* address slave device, write */
  if (i2c_sla_rw(device, 0, TW_MT_SLA_ACK, 1))
    return -2;

  // write to the command register
  addr = 0;

  /* write address */
  if (i2c_data_tx(addr, TW_MT_DATA_ACK, 1))
    return -3;

  /* repeated start condition */
  if (i2c_start(0x10, 1))
    return -4;
  
  cmd = 0xA0;
  
    /* write command */
  if (i2c_data_tx(cmd, TW_MT_DATA_ACK, 1))
    return -5;
	
  cmd = 0xAA;
  
    /* write command */
  if (i2c_data_tx(cmd, TW_MT_DATA_ACK, 1))
    return -6;
	
  cmd = 0xA5;
  
    /* write command */
  if (i2c_data_tx(cmd, TW_MT_DATA_ACK, 1))
    return -7;


    /* write command */
  if (i2c_data_tx(Newdevice, TW_MT_DATA_ACK, 1))
    return -8;

  if (i2c_stop())
    return -9;


  return 0;
}

Do I need to need to write the device and address for each byte of data?