why does my program crash?

#include

#include

#include

using namespace std;

struct Employee $\{$

int id;

string firstName;

int age;

int salary;

int departmentId;

$\}$;

void addEmployee$()\{$

Employee emp;

cout $<<$ "Enter employee id: $"<<$ endl;

cin $>>$ emp.id;

cout $<<$ "Enter employee first name: $"<<$ endl;

cin $>>$ emp.firstName;

cout $<<$ "Enter employee department id: $"<<$ endl;

cin $>>$ emp.departmentId;

cout $<<$ "Enter employee age: $"<<$ endl;

cin $>>$ emp.age;

cout $<<$ "Enter employee salary: $"<<$ endl;

cin $>>$ emp.salary;

ofstream outFile$("$employees$.$txt$",$ ios::app$)$;

if $($outFile$.$is$\_$open$())\{$

outFile $<<$ emp.id $<<$ emp.firstName $<<$ emp.departmentId $<<$ emp.age $<<$ emp.salary $<<$ endl;

outFile.close$()$;

cout $<<$ "Employee data was saved to a file." $<<$ endl;

cout $<<$ endl;

$\}$

else $\{$

cout $<<$ "Error opening file!" $<<$ endl;

$\}$

$\}$

void searchEmployee$()\{$

int searchId;

cout $<<$ "Enter employee id you want to search:" $<<$ endl;

cout $<<"***********************************"<<$ endl;

cin $>>$ searchId;

ifstream inFile$("$employees$.$txt$")$;

if $($inFile$.$is$\_$open$())\{$

Employee emp;

bool found $=$ false;

while $($inFile $>>$ emp.id $>>$ emp.firstName $>>$ emp.departmentId

$>>$ emp.age $>>$ emp.salary$)\{$

if $($emp$.$id $==$ searchId$)\{$

cout $<<$ "Employee id is: $"<<$ emp.id $<<$ endl;

cout $<<$ "Employee name is: $"<<$ emp.firstName $<<$ endl;

cout $<<$ "Employee department id is: $"<<$ emp.departmentId $<<$ endl;

cout $<<$ "Employee age is $"<<$ emp.age $<<$ endl;

cout $<<$ "Employee salary is: $"<<$ emp.salary $<<$ endl;

found $=$ true;

break;

$\}$

$\}$

if $(!$found$)\{$

cout $<<$ "Employee with this id is not found." $<<$ endl;

$\}$

inFile.close$()$;

$\}$

else $\{$

cout $<<$ "Error opening file!" $<<$ endl;

$\}$

$\}$

int main$()\{$

int choice;

do $\{$

cout $<<"***********************************"<<$ endl;

cout $<<"1.$ To add employee data press $1."<<$ endl;

cout $<<"2.$ To search for an employee press $2."<<$ endl;

cout $<<"3.$ Quit the program press $3."<<$ endl;

cout $<<$ "Please enter your choice." $<<$ endl;

cin $>>$ choice;

cout $<<$ "Please enter $1,2,$ or $3."<<$ endl;

cout $<<$ "Thank you for using the program!" $<<$ endl;

switch $($choice$)\{$

case $1$:

addEmployee$()$;

break;

case $2$:

searchEmployee$()$;

break;

case $3$:

break;

$\}$

return $0$;

$\}$

while $($choice $!=3)$;

$\}$