الاضافه في في اول الملف

السلام عليكم ورحمة الله وبركاته واجهت خطا مافهمت وش المقصود منه ولاعرفت كيف اتعامل معه

الي انا ابيه اضيف عنصر في اول الملف هذا الغلط الي من الكوبايلر

--------------------Configuration: Cpp1 - Win32 Debug--------------------

Linking...

Cpp1.obj : error LNK2001: unresolved external symbol "void __cdecl insert_first(struct _iobuf *)" (?insert_first@@YAXPAU_iobuf@@@Z)

Debug/Cpp1.exe : fatal error LNK1120: 1 unresolved externals

Error executing link.exe.

Cpp1.exe - 2 error(s), 0 warning(s)

--------

وهذا البرنامج كامل؟؟؟؟؟

#include<stdio.h>
/*********** Data ***********/
typedef struct {
	int id;
	float gpa;
}data;
/*********** The functions ***********/
void read(data*);
void print(FILE*);
void insert_last(FILE*);
void insert_first(FILE*);
void insert_After_Target(FILE*,int);
void delet_first(FILE*);
int search(FILE*,int);
int size(FILE*);
void copy(FILE*,FILE*);
void menu();
/*********** Main ***********/
int main(){
	data R;
	FILE *f;
	int choice;
	int i,t,n;
	if((f=fopen("f.dat","w"))==NULL)
  printf("sorry i can not open the file\n");
	else{
	for(i=0;i<3;i++){
  read(&R);
  fprintf(f,"%d %.2f ",R.id,R.gpa);
	}
	fclose(f);
	menu();
	scanf("%d",&choice);
	while(choice!=6){
  switch(choice){
  case 1:
 	 insert_first(f);
 	 menu();
 	 break;
  case 2:
 	 insert_last(f);
 	 menu();
 	 break;
  case 3:
 	 printf("Enter the Taget: ");
 	 scanf("%d",&t);
 	 n=search(f,t);
 	 printf("n=%d\n",n);
 	 if(n==1)
 	 insert_After_Target(f,t);
 	 else
    printf("Target not found\n");
 	 menu();
 	 break;
  case 4:
 	 print(f);
 	 menu();
 	 break;
  case 5:
 	 delet_first(f);
 	 menu();
  default :
 	 printf("Error choice try agan\n");
   menu();
 	 break;
  }
  scanf("%d",&choice);
	} 

	}
	return 0;
}

/*********** Menu ***********/
void menu(){
	printf("+------------------------------------------------------+");
	printf("\n|                | The Main Menu |                     |");
	printf("\n+------------------------------------------------------+");
	printf("\n| 1- Inserts a new data in the first.                  |");
	printf("\n| 2- Inserts a new data in the last.                   |");
	printf("\n| 3- Inserts After Target.                             |");
	printf("\n| 4- Print The File.                                   |");	
	printf("\n| 5- Delet First.                                      |");
	printf("\n| 6- End.                                              |");	
	printf("\n+------------------------------------------------------+");
	printf("\nEnter your choice :");
}
/*********** Read ***********/
void read(data *R){
	printf("Enter the id :");
	scanf("%d",&R->id);
	printf("\n");
	printf("Enter the gpa :");
	scanf("%f",&R->gpa);
	printf("\n");
}
/*********** Print ***********/
void print(FILE *f){
	data R;
  if((f=fopen("f.dat","r"))==NULL)
  printf("sorry i can not open the file\n");
	else{
  fscanf(f,"%d %f",&R.id,&R.gpa);
	while(!feof(f)){  
  printf("The id is: %d the gpa is: %.2f\n",R.id,R.gpa);
  fscanf(f,"%d %f",&R.id,&R.gpa);
	}
	fclose(f);
}
}
/*********** Insert Last ***********/
void insert_last(FILE *f){
	data R;
	if((f=fopen("f.dat","a"))==NULL)
  printf("Sorry can not open the file\n");
	else{
  read(&R);
  fprintf(f,"%d %f ",R.id,R.gpa);
  fclose(f);
	}
}
/*********** Insert After Target ***********/
void insert_After_Target(FILE *f,int t){
	FILE *f2;
	data R;
	data Z;
	f=fopen("f.dat","r");
	f2=fopen("f2.dat","w");
	while(!feof(f)){
  fscanf(f,"%d %f ",&R.id,&R.gpa);
  fprintf(f2,"%d %f ",R.id,R.gpa);
  if(R.id==t){
 	 read(&Z);
 	 fprintf(f2,"%d %f ",Z.id,Z.gpa);
  }
	}
	fclose(f);
	fclose(f2);
	f=fopen("f.dat","w");
	f2=fopen("f2.dat","r");
	while(!feof(f2)){
  fscanf(f2,"%d %f ",&R.id,&R.gpa);
  fprintf(f,"%d %f ",R.id,R.gpa);
	}
	fclose(f);
	fclose(f2);
}
/*********** Search ***********/
int search(FILE *f,int t){
	data R;
	int m=0;
	f=fopen("f.dat","r");

	while(!feof(f)){
 	 fscanf(f,"%d %f ",&R.id,&R.gpa);
  if(R.id==t){
    m=1;
    fclose(f);
    return m;
  }

	}
	fclose(f);
	return m=0;

}
/*********** Size ***********/
int size(FILE*f){
	int c=0;
	data R;
	f=fopen("f.dat","r");
	while(!feof(f)){
  fscanf(f,"%d %f ",&R.id,&R.gpa);
  c++;
	}
	fclose(f);
	return c;
}
/*********** Delet First ***********/
void delet_first(FILE *f){
	FILE *f2;
	data R;
	f=fopen("f.dat","r");
	f2=fopen("f2.dat","w");
	fscanf(f,"%d %f ",&R.id,&R.gpa);
	while(!feof(f)){
  fscanf(f,"%d %f ",&R.id,&R.gpa);
  fprintf(f2,"%d %f ",R.id,R.gpa);
	}
	fclose(f);
	fclose(f2);
	f=fopen("f.dat","w");
	f2=fopen("f2.dat","r");
	while(!feof(f2)){
  fscanf(f2,"%d %f ",&R.id,&R.gpa);
  fprintf(f,"%d %f ",R.id,R.gpa);
	}
	fclose(f);
	fclose(f2);
}
/*********** Copy ***********/
void copy(FILE *f,FILE *f2){
	data R;
	while(!feof(f2)){
  fscanf(f2,"%d %f ",&R.id,&R.gpa);
  fprintf(f,"%d %f ",R.id,R.gpa);
	}
}
/*********** Insert First ***********/
void insert_fist(FILE *f){
	FILE *f2;
	data R;
	f=fopen("f.dat","r");
	f2=fopen("f2.dat","w");
	read(&R);
	fprintf(f2,"%d %f ",R.id,R.gpa);
	while(!feof(f)){
  fscanf(f,"%d %f ",&R.id,&R.gpa);
  fprintf(f2,"%d %f ",R.id,R.gpa);
	}
	fclose(f);
	fclose(f2);
	f=fopen("f.dat","w");
	f2=fopen("f2.dat","r");
	while(!feof(f2)){
  fscanf(f2,"%d %f ",&R.id,&R.gpa);
  fprintf(f,"%d %f ",R.id,R.gpa);  
	}
	fclose(f);
	fclose(f2);
}

ان شاءلله الاقي الاجابه عندكم