2051定时器1怎么设置啊,帮帮忙啊!

因为我要用到2051的两个定时器,而且两个都工作在定时器工作方式,但设置T1,却无论如何也不能使灯点亮和闪烁,急啊,请大家帮忙!
#include<at89x51.h>
#define uchar unsigned char
#define uint unsigned int
sbit runled=P3^0;/*启动灯*/
uchar num0;
void main()
{
TMOD=0x10;
TH1=(65535-45872)/256;
TL1=(65535-45872)%256;
EA=1;
ET1=1;
TR1=1;
while(1);
}
void T1_time()interrupt 1
{
TH1=(65535-45872)/256;
TL1=(65535-45872)%256;
num0++;
if(num0==20)
{
num0=0;
runled=~runled;
}
}