Yes,you are right.
But solution was so obviuos that nobody might find it even worth mention or discussion.May be...
Thank you again.With your help I finally finished pretty complicated gauge for the beginner like me-EICAS:

And if you dont mind I ask one more question about XML.
One stupid XML problem is driving me crazy-very simple and classic task:
There is a switch,wich jumps from on to off position.Near the switch there is a simple indicator(lamp),wich supposed to indicate that switch state.
Both gauges uses the same variable to change their state.Very simple.And actually works-I click switch-lamp goes on-one more click-lamp goes off.
The problem is that switch doesnt jump when I click it.

But as I remove the lamp from panel-switch jumps.Two gauges cannot use the same variable as a source?
Thats the XML limitation?Or as in first case I dont see the most obvious?