supertrend value

i made something approaching what i want but i cant understand the behaviour of this EA : its following supertrend switches sometimes, but it also reacts when the market reaches supertrend value...

here are the interresting lines of this code :

//green supertrend and previous value

double super0 = iCustom(NULL,0,"SuperTrend",0,1);
double prevsuper0 = iCustom(NULL,0,"SuperTrend",0,2);

//red supertrend and previous value

double super1 = iCustom(NULL,0,"SuperTrend",1,1);
double prevsuper1 = iCustom(NULL,0,"SuperTrend",1,2);

// turns to red

if ((super1!=2147483647) && (prevsuper1==2147483647)) Order=SIGNAL_CLOSEBUY;

if ((super1!=2147483647) && (prevsuper1==2147483647)) Order=SIGNAL_SELL;

//turns to green

if ((super0!=2147483647) && (prevsuper0==2147483647)) Order=SIGNAL_CLOSESELL;

if ((super0!=2147483647) && (prevsuper0==2147483647)) Order=SIGNAL_BUY;

i also wonder why this weird value of 2147483647 when the line isnt of the same color as the buffer, instead of a clean EMPTY_VALUE...

thanks again!!!