Hi all

Thanks to HenrikOlsson and mister_e that give me the marvelous advice.
I had tested it on the lab but the period is 4.6 and something 4.5. After I change it to For 0 To 2020 it will work 4.3 and something 4.2.
I just measure it using stopwatch.
For accuracy of the clock I will assign TMR0 = 12 {((fosc/4)*(256-12)*256)=0.9994}. Is that OK????

Mister_e has suggest me to use 10us pause. Which mean that the for loop have to increase to 216000 rite???
Sorry..I don't undestand the statement below:-

*****If you need accuracy, you may decide to fine-tune it using MPLAB stopwatch OR measure it using an extra i/o and a scope.
Another solution... Use 2 variables, flags and 1 Timer.*****************