#include "Includes.h"

 
extern void keyscan(void){                                                                     //鍵盤掃描程序  
       unsigned char  co[4]={0,0,0,0};  
       unsigned char sum=0;
	   unsigned char i;                                           
    if(P0_0==0){
     co[0]=1;}
    if(P0_1==0){
     co[1]=1;}
    if(P0_2==0){
     co[2]=1;}
    if(P0_3==0){
     co[3]=1;}	
  		
 for(i=0;i<4;i++){
                   sum+=co[i]; 
                   co[i]=0;  
			      }
   if(sum==1){viewone(); }
}