[amibroker] Buy Error on Embeded coniditonal statement

[tipequity]

I get erroneous buy signal when I use embedded conditional statement. 
For example:
Cond1 = Close > MA(close, 3);
Cond2 = Cond1 and Close>5;
Cond3 = Volume > 100;
Buy = cond2 and cond3;
Is there something that I am missing?