Circuit and Programming: Push Button Switch to Change LED Blink Delay

How connect a push button to a microcontroller (make a circucit) and make a program for the Atmel AVR microcontroller using a push button to change the delay that an LED is blinking. The program uses the util/delay.h library and _delay_ms(delayAmount) function. Two delays are used: a 10 millisecond delay and a 100 millisecond delay.