In a message dated 14/11/2006 19:48:43 GMT Standard Time, bones@xxxxxxx writes: In other words their altimeters will always be set to the value corresponding to the last height clearance issued by ATC. If ATC use "Altitude" altimeters are set to QNH, if they use "Flight Level" you set 1013.2 - irrespective of the current height of the aircraft. Complicated world isn't it? <vbg> Yes! But in that case the pilot must take responsibility for the actual setting, the altitude alert must just act as a reminder, rather than an automatic switch. I've started looking at this, I had a look at macros as explained in the SDK - NOT! I'm now off off for a lie down. Frank T.