var getInitials = function (string) {
var names = string.split(' '),
initials = names[0].substring(0, 1).toUpperCase();
if (names.length > 1) {
initials += names[names.length - 1].substring(0, 1).toUpperCase();
}
return initials;
};
console.log(getInitials('FirstName LastName'));
console.log(getInitials('FirstName MiddleName LastName'));
console.log(getInitials('1stName 2ndName 3rdName 4thName 5thName'));