code help plz

i want to be able to manually plot a line between 2 values and the system shud tell me the range between the 2...

like in the chart if i plot a line between 200 to 150 where 200 and 150 are the price then it should display 50 as the result on that line along with plotting it...

can someone help me with this code...thanx.

use the study() function in conjunction with getchartID()
see the AB help reference for details about them.