单片机keil程序缺少主程序

我这个程序缺少一个主程序控制，我该怎么编写一个主程序
#include<reg51.h>

#define uchar unsigned char

#define uint unsigned int

sbit RED_A=P1^0; //东西向灯

sbit YELLOW_A=P1^1;

sbit GREEN_A=P1^2;

sbit RED_B=P1^3; //南北向灯

sbit YELLOW_B=P1^4;

sbit GREEN_B=P1^5;

uchar Flash_Count=0,Operation_Type=1; //闪烁次数，操作类型变量

//延时

void DelayMS(uint x)

{

uchar i;

while(x--) for(i=0;i<120;i++);

}

//交通灯切换

void Traffic_Light()

{

switch(Operation_Type)

{

case 1: //东西向绿灯与南北向红灯亮

RED_A=1;YELLOW_A=1;GREEN_A=0;

RED_B=0;YELLOW_B=1;GREEN_B=1;

DelayMS(600);

Operation_Type=2;

break;

case 2: //东西向黄灯闪烁，绿灯关闭

DelayMS(90);

YELLOW_A=~YELLOW_A;GREEN_A=1;

if(++Flash_Count!=6) return; //闪烁3次

Flash_Count=0;

Operation_Type=3;

break;

case 3: //东西向红灯，南北向绿灯亮

RED_A=0;YELLOW_A=1;GREEN_A=1;

RED_B=1;YELLOW_B=1;GREEN_B=0;

DelayMS(600);

Operation_Type=4;

break;

case 4: //南北向黄灯闪烁3次

DelayMS(90);

YELLOW_B=~YELLOW_B;GREEN_B=1;

if(++Flash_Count!=6) return;

Flash_Count=0;

Operation_Type=1;

}

}

void main()
{
while(1){Traffic_Light();}
}