To add to what Richard has said, that coe needs a lot of other improvements.
Start by sorting out the indentation - that makes it a lot easier to read, and that means much better reliability and easier maintenance.
Then break it up into separate functions: Each option calls a function (with an appropriate name) to do that job, instead of having the code in one monolithic function. Again, that improves readbility and maintenance.
int main(int argc, char** argv) {
int option;
do {
showMenu();
option = getUserSelection();
switch(option) {
case optLogin: doLogin(); break;
case ...
}
} while (option != optExit);
}
Now you have a manageable chunk of code that is easy to work with and understand - and it's a lot harder to muck up existing code when adding or changing an option. And the added bonus is that it's simpler to match up your curly brackets!
main
now is simple to read - you can understand what it is doing in a glance and all the detail for each option is separated from the others.
Give it a try!