## Add and minus from the text file arent give the right value.

I'm going to try explain the best way i can.

I'm creating a bank system.

So I know to make a deposit to the balance, which add ups what is the balance to i have add.

When i run the deposit function, its work well in some ways. If balance(text file) has the value 10, add i addSum 20, the balance will become 30, same as the text file will become 30. so its work well to add positive number.

Code:
```double deposit(double balance)

{

double addSum = 0;

system("CLS");
cout<< "Welcome to deposit."<<endl;
cout<<"Enter a sum you wish to add to your account:";

fstream myfile;
myfile.open ("money.txt");

cin>> addSum;

balance = addSum + balance;

myfile << balance;

cout << balance << '\n';

system("CLS");
return balance;

}```
When I withdraw from 30 which is the balance, then i takeSum, for example i take away 30. The balance will become 30 - 30 = 0
When i make another withdraw from example -150, it will be -150.

Which shows correct.

But when i make a deposit from -150 and i addSum 130, the balance shows -500, and it should had been -20.

Code:
```double withdraw(double balance)

{
double takeSum = 0;

system("CLS");
cout<< "Welcome to withdraw."<<endl;
cout<<"Enter a sum you wish to take away from your account:";

cout << balance << '\n';

ofstream myfile;
myfile.open ("money.txt");

cin>> takeSum;

balance = balance - takeSum;

myfile << balance;

cout << balance << '\n';

system("CLS");
return balance;
}```
My case statement to understand better.

Code:
```int main()

{
double balance = 0;
balance = currentBalance(balance);
menu(balance);
return 0;
}

// menu function

int menu(double balance)
{

int menuOption = 0;

cout<<" \n---------------------------------------------------"<<endl;
cout<<"If you require help, press 1 for unscreen help. \n"<<endl;

cout<<"Please choose from the following option \n"<<endl;

cout<<"Press 2 for to check balance."<<endl;
cout<<"Press 3 for to make a Withdraw."<<endl;
cout<<"Press 4 for to make a Deposit."<<endl;
cout<<"Press 9 to exit"<<endl;

cin>>menuOption;

switch(menuOption)
{
case 1:
unscreen();
menu(balance);
break;

case 2:
readBalance(balance);
menu(balance);
break;

case 3:
balance = withdraw(balance);
readBalance(balance);
menu(balance);
break;

case 4:
balance = deposit(balance);
readBalance(balance);
menu(balance);
break;

case 9:
exit(0);

default:
cout<<"You did not choose from the menu options, reloading the menu!"<<endl;
main();

return 0;
}

}```
What is causing this problem, also when function deposit and withdraw close, it goes to readBalance function, should go to menu.

Code:
```double readBalance(double balance)
{

int option;

system("CLS");
cout<<"Welcome to balance."<<endl;
cout<<"Your balance is:"<<endl;

string path = "money.txt";							 // Storing your filename in a string
ifstream fin;										 // Declaring an input stream object

fin.open(path);									 // Open the file
if(fin.is_open())									 // If it opened successfully
{
fin >> balance;									// Read the values and
// store them in these variables
fin.close();										// Close the file
}

cout << balance << '\n';

cout<<"\n"<<endl;
cout<<"Press 0 for further action or press 9 to exit." <<endl;

cin >> option;

if (option == 9)
{
exit(0);
}

else if (option == 0 )
{
return balance;
}

else
{
exit(0);
}

}```