/*[[
	Name := GalaherTrade
	Separate Window := Yes
	First Color := Green
	First Draw Type := Line
	First Symbol := 217
	Use Second Data := No
	Second Color := Red
	Second Draw Type := Line
	Second Symbol := 218
]]*/
Inputs : Dep(1000), per(20);
Variable : shift(0), i(0), mmin(0), mmax(0);

SetLoopCount(0);
// loop from first bar to current bar (with shift=0)

//For shift = Bars-1-per Downto 0 Begin
For shift = 1000 Downto 0 Begin
  mmin=L[shift+per];
  mmax=H[shift+per];
  for i=shift+per Downto shift Begin
    if H[i]>mmax then mmax=H[i];
    if L[i]<mmin then mmin=L[i]; 
  end;
  SetIndexValue(shift-1, ((h[shift]+l[shift])/2)-((mmax+mmin)/2));
  
End;
  
  //c[shift]