javascript - How can I make a countdown timer in PHP? -

how can make countdown timer in php starts @ 40 seconds , counts in format:

40.59 - 40.48 - 40.47 - etc etc

i need button resets it.

is possible in php? need use javascript?

you need javascript achieve timer.

some useful resources:

http://www.elated.com/articles/javascript-timers-with-settimeout-and-setinterval/

http://www.dynamicdrive.com/forums/showthread.php?t=61593

http://www.devshed.com/c/a/javascript/using-timers-in-javascript/