Whats wrong with the plot function??

[ronylts]

_SECTION_BEGIN("Price");
SetChartOptions(0,chartShowArrows|chartShowDates);
_N(Title = StrFormat("{{NAME}} - {{INTERVAL}} {{DATE}} Open %g, Hi %g, Lo %g, Close %g (%.1f%%) {{VALUES}}", O, H, L, C, SelectedValue( ROC( C, 1 ) ) ));
Plot( C, "Close", ParamColor("Color", colorDefault ), styleNoTitle | ParamStyle("Style") | GetPriceStyle() );
_SECTION_END();

x1=10000 * (Now(8)-1 - 1900) + 100 * Now(7) + Now(6);
x2=ValueWhen(DateNum()==x1,BarIndex(),1);
x3=BarIndex()-x2;
Plot(x3,"ff",colorRed,styleLine);