Woop

#include <iostream>
#include <string>
using namespace std;

void cryptonise();
void decryptonise();
void more_info();

int main()
{

    system("title Shahin's crypto-machine");

while(true)
           {

string choice;

do
{
    system("cls");
cout <<"What would you like to do?\n"
     <<"1. Encrypt a string of text\n"
     <<"2. Decrypt a string of text\n"
     <<"3. More info\n"
     <<"4. Exit program\n\n";

    cout <<"Your choice?: ";
    cin>>choice;
    cout <<endl<<endl;
}while(choice !="1" && choice !="2" && choice != "3" && choice != "4");

system("cls");

if(choice=="4") return 0;
if(choice=="1") cryptonise();
else if(choice=="2")decryptonise();
else more_info();



           }
return 0;
}

void cryptonise()
{
    string text;
    cout <<"What would you like to \"cryptonise\"?:\n";
    cin.get();   getline(cin,text);

 cout <<"\nEncrypted text:\n";
for(int i=0; i<text.size(); i++)
    {
        int coop = text[i];

        if(i%2==0)
        {
            cout <<(char)(coop+33);
        }
        else
        {
            cout <<(char) (coop+18);
        }
    }

cout<<endl<<"\nPress [ENTER] to go back to the menu.";cin.get();

}

void decryptonise()
{
    string text2;
    cout <<"What would you like to \"decryptonise\"?:\n";
     cin.get();   getline(cin,text2);

  cout <<"\nDecrypted text:\n";

for(int i=0; i<text2.size(); i++)
    {
        int coop2 = text2[i];

        if(i%2==0)
        {
            cout <<(char)(coop2-33);
        }
        else
        {
            cout <<(char) (coop2-18);
        }
    }
    cout<<endl<<"\nPress [ENTER] to go back to the menu.";cin.get();
}

void more_info()
{
    system("cls");

    cout <<"When you start this program, you can either \n* encrypt text,\n* decrypt text(text that has been encrypted by a copy of this program)\n* exit the program.";
    cout <<"\n\nYou can copy encrypted text(to send to someone)\nor paste some encrypted text that you want to decrypt by:\n\n"
         <<"* Right click in the program, and select the choice to mark text.\n  When you have done so, right click on the highlighted text.\n\n"
         <<"* Right click in the program and select paste\n";

         cout <<"\nPress [ENTER] to go back to the menu.";cin.get();cin.get();
}