我这个Proteus的图有什么问题？？？

我想实现的是让发光二极管D12由灭到均匀变亮到最亮之后均匀熄灭，且在最亮和最灭的时候蜂鸣器报警一次，但是他不会发亮和警报（以下是我的代码）
#include <reg52.h>
#define uchar unsigned char
#define uint unsigned int
sbit dula = P2^6;
sbit wela = P2^7;
sbit dawr = P3^6;
sbit dacs = P3^2;
sbit beep = P2^3;
void delay(uint z)
{
    uint i,j;
    for(i = z;i > 0;i--)
    for(j = 110;j > 0;j--);
}
void main()
{
    uchar val,flag;
    dula = 0;
    wela = 0;
    dacs = 0;
    dawr = 0;
    P0 = 0;
    while(1)
    {
        if(flag == 0)
        {
            val += 9;
            P0 = val;
            if(val == 255)
            {
                flag = 1;
                beep = 0;
                delay(100);
                beep = 1;
            }
            delay(322);
        }
        else
        {
            val -= 9;
            P0 = val;
            if(val == 0)
            {
                flag = 0;
                beep = 0;
                delay(100);
                beep = 1;
            }
            delay(322);
        }
    }   
}