Substitution cipher

#include <iostream>
using namespace std;
const char REAL_ALPHABETH[26] = {'A', 'B' , 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R' , 'S' , 'T', 'U', 'V', 'W','X','Y','Z' };
int orderIntheAlphabeth(char letter) {
	int order=0;
	for (int i = 0; i < strlen(REAL_ALPHABETH); ++i) {
		if (toupper(letter) == REAL_ALPHABETH[i]) {
			order = i;
		}
	}
	return order+1;
}
bool validateKey(char* key) {
	if (strlen(key) != 26) {
		cout << "Invalid key. It must be 26 symbols.";
		return false;
	}else {
		for (int i = 0; i < strlen(key); ++i) {
			if (!isalpha(key[i])) {
				cout << "Only letters are allowed to the key!";
				return false;
			}
			for (int j = 0; j < strlen(key); ++j) {
				if (key[i] == key[j] && i != j) {
					cout << "No repeating sharacters allowed!";
					return false;
				}
			}
		}
	}

	return true;
}
int main()
{
	char* alphabeth = new (nothrow) char[27];
	char *crypt= new (nothrow) char [100];
	cout << "Enter your cipher: ";
	cin.getline(alphabeth, 27);
	while (validateKey(alphabeth)==false) {
		cout << "Try another!";
		cin.clear();
		cin.getline(alphabeth, 27);
	}
	cout << "Enter your text: ";
	cin.clear();
	cin.getline(crypt, 100);
	for (int i = 0; i < strlen(crypt); ++i) {
		if (isalpha(crypt[i])) {
			int order = orderIntheAlphabeth(crypt[i]);
			crypt[i] = alphabeth[order-1];
		}
	}
	for (int i = 0; i < strlen(crypt); ++i) {
		cout << crypt[i];
	}
	delete[] alphabeth;
	delete[] crypt;
	return 0;
}