Hi, I'm writing excercises to know better Zorro.

Below you can find script, which calculates and plots differences for every hour bar from daily open (fx).

Code:
// Script generates chart for differences between day open price (midnight for fx market) and every bar according to defined bar period.
// author: NightWalker @ Zorro Trader Forum
// version: 20121202.

function run()
{
	BarPeriod = 60; //time frame set to 1 hour
	StartDate = 2012; //testing just for 2012 year
	NumDays = 30; // and only 30 days
	 
	TimeFrame = 24; //switchitng time frame - price series below reference to daily frame (24 * BarPeriod))
	var daily_atr = ATR(1);

	TimeFrame = 1; //switching timeframe to 1 hour and printf debugging info
	printf("\n close = %f, daily-open = %f, atr = %f", priceClose(0), priceOpen(hour(0)), daily_atr);
	
	var pricediff = (priceClose(0) - priceOpen(hour(0)))/daily_atr*PIP; //calculate difference in price
	// hour(0) means current price, so priceOpen(hour(0)) points to daily open (for fx markets - midnight))

	if ( hour(0) == 0)	// ploting big red bar separating days instead of first hour bar
		plot("new day", daily_atr, BARS, RED);
	else
		plot("price differences", pricediff, BARS, BLUE);	//plot price difference for current bar
		
	PlotHeight1 = 300;
		
	set(PLOTNOW);
}

NightWalker