#include <lpc213x.h>

#define RED_LED	0x00000400	//set p0.10 as RED LED
#define SW3		0x00100000	//set p0.20 as SW3

int  main(void)
{
long tmp;			// variable for temporary storage of port 0  status
int flag;

	IO0DIR = RED_LED;		// set p0.10 as output
	tmp = IO0PIN & SW3;			// read SW3 (p0.20)
	while(1) {	
		while(tmp==0) tmp = IO0PIN & SW3;			// wait SW3 (p0.20) change to high
		while(tmp!=0) tmp = IO0PIN & SW3;			// wait SW3 (p0.20) change to low
		if(flag==0) {
			flag = 1;
			IO0SET = RED_LED;
		}
		else {
			flag = 0;
			IO0CLR = RED_LED;
		}
	}
 }