You need to perform either a software or hardware debounce if you are planning to use a switch or push button because it will have a transitory oscilating between 0 and 1

I like maxim products so i will recommend IC that performs debounce (SOT) with 2 inputs
http://para.maxim-ic.com/compare.a...rs.cfm&ln=

Or you can use some other hardware like the ones here
http://members.shaw.ca/roma/six.html

There are many ways to perform hardware debounce

If you don't like hardware you can debounce it with a delay (disable int0 & int1 when entering the ISR, then a delay and enable it when finish).. i haven't done this but i would give it a try (it will waste precious cycles in this delay). For the delay you have to read the datasheet of the switch and see how much does time takes for the transitory.

the are many many ways to perform software debouncing like the one that Mr. Steve Taylor http://www.8052.com/forum/rea...&top=76312 and http://www.8052.com/forum/rea...&top=77417 from Mr Graham Cole

It's up to you to choose the one best fits your application, good luck!

Regards