求高手帮忙。

#include<reg52.h>
sbit wei=P2^3;
sbit duan=P2^2;
unsigned char code duanma[10]={0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f};// 显示段码值0~9
unsigned char code weima[]={0xfe,0xfd,0xfb,0xf7,0xef,0xdf,0xbf,0x7f};//分别对应相应的数码管点亮,即位码
unsigned char fen,shi,miao,k;
void main (void)
{ P0=0x24;
 wei=1;
 wei=0;
 P0=duanma[0];
 duan=1;
 duan=0;
 k=0;
 P1=0x01;
    TMOD=0x01;
    EA=1;
    ET0=1;
    TH0=(65536-50000)/256;
    TL0=(65536-50000)%256;
    TR0=1;
 while(1);
}
void dingshi0() interrupt 1  //定时器0中断程序
{        TH0=(65536-50000)/256;
         TL0=(65536-50000)%256;
         k++;
         if(k==20)
         { miao++;
             k=0;
             P0=weima[7];
             wei=1;
             wei=0;
             P0=duanma[miao%10];
             duan=1;
             duan=0;
             P0=weima[6];
             wei=1;
             wei=0;
             P0=duanma[miao/10];
             duan=1;
             duan=0;
                 P1=~P1;
               if(59==miao)
               { miao=0;
                         P0=weima[7];
                         wei=1;
                         wei=0;
                         P0=duanma[miao%10];
                         duan=1;
                         duan=0;
                         P0=weima[6];
                         wei=1;
                         wei=0;
                         P0=duanma[miao/10];
                         duan=1;
                         duan=0;
                         fen++; //显示分钟数码管
                         P0=weima[4];
                         wei=1;
                         wei=0;
                         P0=duanma[fen%10];
                         duan=1;
                         duan=0;
                         P0=weima[3];
                         wei=1;
                         wei=0;
                         P0=duanma[fen/10];
                         duan=1;
                         duan=0;

                 if(59==fen)
                 {
                         fen=0;
                         P0=weima[4];
                         wei=1;
                         wei=0;
                         P0=duanma[fen%10];
                         duan=1;
                         duan=0;
                         P0=weima[3];
                         wei=1;
                         wei=0;
                         P0=duanma[fen/10];
                         duan=1;
                         duan=0;
                         shi++;
                         P0=weima[1];
                         wei=1;
                         wei=0;
                         P0=duanma[shi%10];
                         duan=1;
                         duan=0;
                         P0=weima[0];
                         wei=1;
                         wei=0;
                         P0=duanma[shi/10];
                         duan=1;
                         duan=0;
                                           }
                if(24==shi)
                {
                    P0=0x24;
                     wei=1;
                     wei=0;
                     P0=duanma[0];
                     duan=1;
                     duan=0;     
                }                         
               }             
         }
   }
不知道哪儿错了 定时器能正正常运行（LED会闪烁说明可以进到IF(20=k)程序）可结果 不是按 我预想的 电子钟表  而是 秒的 十位 的数码管计数  其他的数码管全部是黑的 求高手解答。

求帮忙

嘿。。。。中断服务函数为么要做这么多事啊。