Missing data in a Multi-Data chart

["jonmac" <jonmac@xxxxxxxxxxx>]

Hello,

In a multi-data chart I'm trying to exit at market where data4 has no data
(ie: data1 in Aus is a trade day and data4 in US is, say, a holiday).

Having tried exits such as;
If MarketPosition = 1 and data4 =0 then exitlong at market;

and
xxBlank = NumToStr(close of data4,decimals);
If MarketPosition = 1 and xxBlank="" then exitlong at market;

then any of these fail to execute.

Strangely the print log for close of data4 on the date with no bar shows
what could be a valid value for that data series!

Any help greatly appreciated.
Thanks
Jon