代码编译错误，帮我修改一下

Params Numeric length(30); Numeric i(100); Numeric lots(1); Vars Series<Numeric> mta; Series<Numeric> mtb; Numeric LRSlope; Numeric LRAngle; Numeric LRIntercept; Numeric LRValue; Numeric LRSlope1; Numeric LRAngle1; Numeric LRIntercept1; Numeric LRValue1; Numeric mt; Begin LinearReg(Close[1],length,0,LRSlope, LRAngle, LRIntercept, LRValue); mta=LRSlope; LinearReg(mta*50,length,0,LRSlope1, LRAngle1, LRIntercept1, LRValue1); mtb=LRSlope1; mt=mta*mtb*50; //{ if(MarketPosition!=1 And mt>I And mta>0) { if(MarketPosition==-1) BuyToCover(0,0); Else Buy(lots,Open); } if(MarketPosition!=-1 And mt>I And mta<0) { if(MarketPosition==1) Sell(0,0); Else SellShort(lots,Open); } if(MarketPosition==1 and mt<0) Sell(lots,0); if(MarketPosition==-1 and mt<0) BuyToCover(lots,0); End