function validateLogin() { 
	userLogin = document.getElementById('userlogin');

	if (userLogin.value == "") { 
		userLogin.focus();
		// alert("Fill in your Login.");
		return false;
	}
	else {
		var regexLogin = /^[a-zA-Z0-9]{3,16}$/;
		if (!regexLogin.test(userLogin.value)) {
			userLogin.focus();
			alert(
				'Login is invalid format.\n' +
				'\n' +
				'Only letters, and numbers are allowed.\n' +
				'No spaces allowed.\n' + 
				'At least 3, and no more than 16 characters in length.'
			);
			return false;
		}
	}

	userPW = document.getElementById('userpw');
	if (userPW.value == "") { 
		userPW.focus();
		// alert("Fill in your Password.");
		return false;
	}
	else {
		var regexPW = /^[a-zA-Z0-9]{4,16}$/;
		if (!regexPW.test(userPW.value)) {
			userPW.focus();
			alert(
				'Password is invalid format.\n' +
				'\n' +
				'Only letters, and numbers are allowed.\n' +
				'No spaces allowed.\n' +
				'At least 4, and no more than 16 characters in length.'
			);
			return false;
		}
	}
}