Regex dont work, why not?

JavaScript
1

could anyone look at this script and tell me why this regex do not work. ?

function validation(){

	var firstName = document.getElementById('firstName').value;
	var lastName = document.getElementById('lname').value;
	var email = document.getElementById('email').value;
	var phone = document.getElementById('phone').value;
	

	// regex def

	var firstNamecheck = /^[A-Za-z. ]{3,30}$/ ;
	var lastnamecheck = /^[A-Za-z. ]{3,30}$/ ;
	var emailcheck = /^[A-Za-z]{3,}@[A-Za-z]{3,}[.]{1}[A-Za-z.]{2,6}$/ ;
	var phonecheck = /^[0-9]{9}$/ ;


	// firstName 

	if(firstNamecheck.test(firstName)) {
		document.getElementById('fnerror').innerHTML = "";
	}else{
		document.getElementById('fnerror').innerHTML = "** FirstName is empty ";
	}

	// lastName



	if(lastnamecheck.test(lname)) {
		document.getElementById('lnerror').innerHTML = " ";
	}else{
		document.getElementById('lnerror').innerHTML = "** LastName is empty ";
	}


	// // email

	if(emailcheck.test(email)) {
		document.getElementById('error').innerHTML = " ";
	 }else{
	 	document.getElementById('error').innerHTML = "** email is empty ";
	 }

	// phone

	if(phonecheck.test(phone)) {
	 	document.getElementById('phonecheck').innerHTML = " ";
	 }else{
	 	document.getElementById('perror').innerHTML = "** phone is empty ";
	 }

};