大神帮我看看为什么这程序在51单片机上不能运行

#include<reg52.h>
#define uint unsigned int
#define uchar unsigned char
sbit an=P2^0;
sbit feng=P1^5;
uchar code table[]={0xfe,0xfd,0xfb,0xf7,0xef,0xdf,0xbf,0x7f};
uchar num;
void delay(uchar x)
{ uchar z,y,c;
for(z=x;z>0;z--)
for(c=1000;z>0;z--)
for(y=120;y>0;y--);
}
void FM()
{
feng=1;
delay(1);
feng=0;
delay(1);
feng=1;
delay(1);
feng=0;
}
void init()
{
feng=0;
num=0;
P0=0xfe;
}
mian()
{
init();
while(1)
{
if(an==0)
{ delay(1);
if(an==0)
{ while(!an);
FM();
}
}
}
}