Just starting out in this programming adventure, and I've run into a problem already with my getline function and else if.

Here is my code:

#include <iostream>

using namespace std;

int main ()
{
    int billy;
    int jill;

    cout << "How old is Billy? " << "\n";
    getline( cin, billy, '\n');

    cout << "Okay!  Now, how old is Jill? " << "\n";
    getline ( cin, jill);

    if ( ( billy > 100 ) && ( jill > 100 ) );
    {
        cout << "Wow!  Those guys are ******* old!";
    }
    else if ( billy > jill );
    {
        cout << "Okay, so Billy is older than Jill.  Expected.";
    }
    else ( billy < jill );
    {
        cout << "Wait, so Jill was older than Bill?  Interesting.";
    }
}

Now it my compiler (I'm using code::blocks) says that there's no matching function for all to getline. It works just fine if I switch it to:

cin >> billy

So, I'm not sure what's wrong with the code. I've reread the instruction book I have explaining getline, but it doesn't exactly explain the full use of it.

And secondly, when I switch the getline to cin >>, when my compiler get's to the else if statement, it says: error: 'else' without a previous 'if'

So, thanks ahead of time for any help, I'd definitely like to get past this point, and I don't want to move on before fully understanding what I've learned.

if (something == something_else);   // this is an empty if (expression) test, that does nothing

{
    // this codeblock is effectively a 'scope,'
    // however, it is not related to the above if statement in any way
}

if (something == something_else)
     one_line(of, &code);   // this if statement has one line of code, because there are no {}

while (something == something_else)
     one_line(of, &code);   // this while loop has one line of code, because there are no {}

if (something == something_else)
{
   // this if (expression) has a code block, that
   // allows for multiple lines of code to be executed if the test was true
   
   int a = 0; // this variable is dead as soon as we hit a }
}

Thank you so much guys! I wasn't aware getline was part of <string> and I got so used to a semi-colon going at the end of everything, that I must've blocked out the part where it says NOT to put them in the if/else statements.