Support and resistance range for Amibroker (AFL)

Av=MA(abs(C-Ref(C,-1)),5);
r1=(C+Av);
r2=(C+(2*Av));
s1=(C-Av);
s2=(C-(2*Av));
Plot (Close,"",3,128);
Plot (r1,"",24,16+8);
Plot (r2,"",24,16+8);
Plot (s1,"",26,16+8);
Plot (s2,"",26,16+8);
GraphXSpace=5;
Title=Name ()+ "Support and resistance Range "+"\n"+ "RES =" + WriteVal  (r1,1.2) + ", "+ WriteVal  (r2,1.2) + "  " + " SUPP= "+ WriteVal (s1,1.2)+ ", " + WriteVal(s2,1.2) ;