Hi Simon,

SA> SA>> And here's how I'm trying to manipulate it:

SA> SA>> m.Attribute&=0x01;
SA> SA>> m.Attribute |= 0x02;
SA> SA>> m.Attribute &= 0x04;
SA> SA>> m.Attribute &= 0x08;
SA> SA>> m.Attribute |= 0x10;
SA> SA>> m.Attribute &= 0x20;
SA> SA>> m.Attribute &= 0x40;
SA> SA>> m.Attribute &= 0x80;

SA> DN> Each of the above statements "steps on" its
predecessor. The result
SA> DN> will always be 0x00 in m.Attribute. This is because each operation
SA> DN> affects the full byte, not just the bit you are after.

SA>Aha! Thanks again David, not just a pretty face.

Not even a pretty face... But what a knowledge of programming languages!

SA> DN>   if (m.Typ == EchoMail)
SA> DN>       m.Attribute ^= 0x01; /* Toggle bit 0 */
SA> DN>   m.Attribute &= 0x01;  /* Switch off all except bit 0
(left alone) */
SA> DN>   m.Attribute |= 0x12;  /* Switch on bits 1 and 4 */

SA> DN> This toggles bit 0 if it is echomail, switches off all other bits and
SA> DN> then switches on bits 1 and 4.

SA>I /think/ I've got it this time. If not, I'll be back. :)

To try to make sure you aren't on this :-).
The normal way of doing things is:

#define BIT_MASK  0x02

then

  m.Attribute &= BIT_MASK;   /* Switch off eveything _except_ bit */
  m.Attribute &= ~BIT_MASK;  /* Switch off bit */
  m.Attribute |= BIT_MASK;   /* Switch on bit */
  m.Attribute |= ~BIT_MASK;  /* Switch on eveything _except_ bit */
  m.Attribute ^= BIT_MASK;   /* Toggle bit */
  m.Attribute ^= ~BIT_MASK;  /* Toggle eveything _except_ bit */

George

 * SLMR 2.1a * Computers eliminate spare time.

--- Maximus/2 3.01