#include<reg51.h>
sbit LED1 = P1^0;
sbit LED2 = P1^1;
void delay10ms(unsigned int c)
{
unsigned char a,b; for(;c>0;c--) for(b=38;b>0;b--)for(a=130;a>0;a--);
}
void main()
{ ?while(1)
{ LED1 = 0; delay10ms(100); LED1 = 1; LED2 = 0; delay10ms(100); LED2 = 1; }}