[amibroker] what's the difference in this code?

[fsmart21]

using a system with a 15 min interval on a day session chart.  trying 
to determine if yesterdays open is greater or less than yesterdays 
close as a filter .  the 2nd attempt returns results which are much 
different than the first section of code.

1st attempt:
prevopen1=TimeFrameGetPrice( "o", inDaily, -1) ;
prevclose1=TimeFrameGetPrice( "c", inDaily, -1);

2nd attempt:
TimeFrameSet( inDaily ); 
prevclose=Ref(C,-1);
prevopen=Ref(O,-1);
TimeFrameRestore(); 

prevclose=TimeFrameExpand(prevclose, inDaily );
prevopen=TimeFrameExpand(prevopen, inDaily);