thanks ijaz
well actually im tryin to read pulses from a telephone so te total time of one pulse is approx 100 ms ....in which 40ms is low time and 60 ms is high time ,,,,,,so in order to detect the pulse and read it ... i have to call delay ... but if i use delay then the control will be busy and another pulse from 2nd telephone set wont be deteteted.....
tht y i thought instead of using delay i may calculate the time b/w low and high time of pulse