这段程序用KeilC编程有什么错误啊？

"MAIN.H"
#define Phone_Num 4
#define true 1
#define false 0
sbit VHSD1=0x90;
sbit VHSD2=0x91;
sbit VHSD3=0x92;
sbit VHSD4=0x93;
sbit DTMFC1=0x94;
sbit DTMFC2=0x95;
sbit DTMFC3=0x96;
sbit DTMFC4=0x97;