#include "reg51.h"
void main()
{	unsigned char KeyValue;
	for(;;)
	{	P3|=0x3c;
		KeyValue=P3;
		switch(KeyValue)
		{	case 0xfb:P1=0xee;break;
			case 0xf7:P1=0xdd;break;
			case 0xef:P1=0xbb;break;
            case 0xdf:P1=0x77;break;
		}
	}
}