This indicator is from jose Silva 

{Trendline - adjustable} 

{©Copyright 2003 Jose Silva} 

pds:= 
Input("average trend length periods",2,252,21); 
pr:=Input("use Open=1 High=2 Low=3 Close=4 Volume=5 MP=6",1,6,4); 
display:=Input("Trend line = 1, Trend points = 2",1,2,1); 

{define events} 
pr:=If(pr=1,O,If(pr=2,H,If(pr=3,L,If(pr=5,V, 
If(pr=6,MP(),C))))); 
price1:=pr; 
price2:=pr; 
time1:=price1>Ref(HHV(price1,pds),-1); 
time2:=price2<Ref(LLV(price2,pds),-1); 

{restrict to last events} 
time1:=time1 
AND Cum(time1)=LastValue(Cum(time1)); 
time2:=time2 
AND Cum(time2)=LastValue(Cum(time2)); 

{sort events} 
t1pds:=LastValue(BarsSince(time1)); 
t2pds:=LastValue(BarsSince(time2)); 
x1:=If(t1pds>=t2pds,time1,time2); 
x2:=If(t1pds>=t2pds,time2,time1); 
y1:=If(t1pds>=t2pds,price1,price2); 
y2:=If(t1pds>=t2pds,price2,price1); 

{fix coordinates} 
y1:=ValueWhen(1,x1,y1); 
y2:=LastValue(ValueWhen(1,x2,y2)); 
b1:=LastValue(BarsSince(x1)); 
b2:=LastValue(BarsSince(x2)); 
plot:=y1+BarsSince(x1)*(y2-y1)/(b1-b2); 

If(display=1,plot,Time1+Time2)