Hi Raghu,

This method of changing a four digit number seems complicated and time consuming. If you have at least three keys then the following method may be faster and simpler for the user to master:

1) Display the old number.
2) Use the UP or DOWN key to increment or decrement the number.
3) Continue to increment or decrement the number four times per second if the UP or DOWN key is held down for longer than 1/4 second.
4) Continue to increment or decrement the number by ten every 1/4 second if the UP or DOWN key is held down for more than 2-1/2 seconds.
5) Continue to increment or decrement the number by 100 every 1/4 second if the UP or DOWN key is held down for more than 10 seconds.
6) Save the number if the ENTER key is pressed.

Regards,

Bert