MetaTrader 4 - Expert Advisor help needed

hi,

i'm using the Expert Advisor and choosing 1H in the PERIOD option.
in the code i call the following functions:
iLow("EURUSD",PERIOD_H1,1);
iLow("EURUSD",PERIOD_M15,1);

and place a buy order after checking some conditions.

the problem is that the expert behaves differently (opening buy orders in different places) when choosing 15M as the PERIOD for the advisor although it shouldn't really matter WHICH period i choose, right? since i call the function iLow and specify to which period to go to.

so my question is: why does it matter which PERIOD i choose in the advisor option when i call for iLow function with a specific period?

If one of your criterias for opening a trade is the iLow value, then it must have an impact when you choose a different time frame.
The indicator has different values on different time frames, just go to metatrader and see for your self. The smaller the time frame, the faster the indicator will react to smaller price changes, as it has more bars to analyze for the recent period.

Hope that makes sense.

thanks for answering.
in the code i use these two lines:
iLow("EURUSD",PERIOD_H1,1);
iLow("EURUSD",PERIOD_M15,1);

however, i get 2 different results if i run the code in EA with the PERIOD option set to M15 and in H1.

but since i call iLow and specify PERIOD_H1 and PERIOD_M15, why does it matter which PERIOD i choose in the EA settings tab?

thanks