Hi, I am plotting some indicators and if I plot the EMA using this code:

Code:
function run()
{  
  BarPeriod = 240;
  StartDate = 2010;
  set(TICKS); 	
  asset("EUR/USD");
  set(PLOTNOW);
  vars Price = series(price());
  var ema = EMA(Price,26);  
  plot("ZMA",ema,MAIN,RED); 
  plot("Price",Price[0],MAIN,BLACK);  
}


it plots:



But when using this code to plot ZMA:

Code:
function run()
{  
  BarPeriod = 240;
  StartDate = 2010;
  set(TICKS); 	
  asset("EUR/USD");
  set(PLOTNOW);
  vars Price = series(price());  
  var zma = ZMA(Price,0);
  plot("ZMA",zma,MAIN,RED); 
  plot("Price",Price[0],MAIN,BLACK);  
}


it plots:



What is wrong? I expected a line not those bars.

Also, what is the meaning of the numbers on top of the graph? (Op,Hi,Lo,CI,ZMA and Price), I did not find it in the documentation. Thanks beforehand!