running a loop to examine the pivots tested  [SOLVED]

Hi, I am writing a program to track all the pivots in the charts and draw a horizontal trendline btw the pivot and the bar that test it.
when i ran the pivot part alone, it would run from the beginning to the end (about 500 bars); when i introduce the testing pivot part, calculated by running a loop to compare every pivot in the past to the current bar, the program only ran from 300th bar to the end.
i examined the code and couldn't figure out why. any help is appreciate!
sean

I checked the occasion when the program will not run from the beginning and i noticed that MaxBarsBack has been reset to a rather large number, in this case it's been reset to 1307 while there are totally 1600 bars.

why is the maxbarsback reset and how can i prevent it from being reset? thanks a lot!

When detected automatically, MaxBarsBack will initially be set to the value of the largest data offset in the study; however, if a variable data offset is used in the script, the initial MaxBarsBack value may prove to be too small.

In such a case, the MaxBarsBack value will automatically be increased by 5 or by a factor of 1.618, whichever yields a higher value, and the study recalculated.

The process of automatic MaxBarsBack detection may cause some functions to be executed repeatedly for the first few bars of a chart when a study is first applied; this can be avoided by setting the MaxBarsBack value manually.