a fingerprint verification program

but programing contian errors without header file

but programing contian errors without header file

in th project error is there is no. h file

#include<reg52.h>
#include<lcd.h>
#include<serial.h>
#include<string.h>
sbit SW = P3^7;
sbit motor1 = P2^0;
unsigned char D[20];
unsigned char i,value;
bit flag;
void Disp_Hex(unsigned char);
void FINGER_FUN_IDT(); // finger
identification
void serial(void ) interrupt 4 {
if (RI)
{ D[i] = SBUF;
if (i>15){flag=1;}
else i++;
} }
void main()
{ bit scan_flag;
SConfig();
scan_flag=0;motor1= 0;
LCD_Init();
LCD_Cmd(0x80);
Disp_Str(" WELCOME ");
Delay(50);clear();
LCD_Cmd(0x80);
Disp_Str(" finger print ");
LCD_Cmd(0xC0);
Disp_Str(" BASED PROJECT ");
Delay(100);
LCD_Cmd(0x80);
Disp_Str(" PRESS SWITCH ");
while(1) // infinite loop
{ LCD_Cmd(0x80);Disp_Str(" PRESS
SWITCH ");
if (SW==0) //scanning switch
{ FINGER_FUN_IDT(); //command
identify function
EA=1;ES=1;
Delay(300);
} if (flag==1)
{ flag=0;
if (D[12] == 0x00 && D[13] ==
0x00 && D[14] == 0x00)
{ scan_flag=1;
LCD_Cmd(0x80);
Disp_Str(" VALID ");
LCD_Cmd(0xC0);
Disp_Str(" PERSON1 ");
} else if (D[12] == 0x00 && D[13]
== 0x00 && D[14] == 0x01)
{ scan_flag=1;
LCD_Cmd(0x80);
Disp_Str(" VALID ");
LCD_Cmd(0xC0);
Disp_Str(" PERSON2 ");
} else if (D[12] == 0x00 && D[13]
== 0x00 && D[14] == 0x02)
{ scan_flag=1;
LCD_Cmd(0x80);
Disp_Str(" VALID ");
LCD_Cmd(0xC0);
Disp_Str(" PERSON3 ");
} else if (D[12] == 0x02)
{ LCD_Cmd(0xC0);
Disp_Str("NO F.P ON SENSOR");
} else if (D[12] == 0x09)
{ LCD_Cmd(0xC0);
Disp_Str("NO F.Pwere FOUND");
} EA=ES=0;
} if (scan_flag==1)
{ Delay(100);
LCD_Cmd(0x80);
Disp_Str(" DOOOR OPEN ");
motor1=0;
Delay(600);
LCD_Cmd(0x80);
Disp_Str(" DOOR CLOSED ");
motor1=1;
Delay(600);
motor1=0;
} } //infinite loop end
} // main loop end
void FINGER_FUN_IDT()
{ Send_Char(0xEF);Send_Char(0x01);
Send_Char(0xFF);Send_Char
(0xFF);Send_Char(0xFF);Send_Char
(0xFF);
Send_Char(0x01);
Send_Char(0x00);Send_Char(0x03);
Send_Char(0x01);
Send_Char(0x00);Send_Char(0x05);
}