Setting The Trend

["Tom" <profilic@xxxxxxxx>]

I am trying to write a signal whereby:

I want to trade with the trend which I define as UP when the High has
penetrated the upperenvelope of a moving average envelopw and remains UP
until the lower envelope is penetrated, even if the price is trading between
the upper and lower. The trend is DOWN when the lower envelope has been
penetrated by the low and stays down until the upper envelope is penetrated
by the high. These are my conditions 1 & 2. 

I then have a trigger condition nested under each condition for my long and
short positions so that only long positions can be signaled in the UP trend
and short in the down.

My problem is that the trigger will not activate if the price is between the
two envelopes. 

How can I set a switch when each penetration takes place so that the trades
take place as I want them to?

Thanks for your help.

Tom