[amibroker] BarsSince giving unexpected result

[Graham Johnson]

I'm wanting to test the number of bars since a security had equal High 
and Low - seemed simple.

vTmp = BarsSince(High == Low);

Works fine where there has been High == Low, but when there hasn't 
been, it returns 0 for all bars.

Is there a workaround, or should I be using a different function.

Thanks

Graham