[amibroker] Random Backtesting

[mikk12345]

Hi, This is what i want to do. I have 10 stocks in my ticker list. I want to 
randomly select 5 long and 5 short each worth 100,000 and hold for 50 days in 
the backtester.

Ive tried the following:-

Buy= 1;
Sell= 0;
Short=1;
Cover=0;
ApplyStop(stopTypeNBar,stopModeBars,50,1);

PositionScore=Random();

PositionSize=100000;

Ive put 1,000,000 in the equity box.

This only returns long only.

Best Regards,

Mikey.