function validaEmail(email){
	ER = new RegExp("^[_a-z0-9-]+(\.[_a-z0-9-]+)*@[a-z0-9-]{2,64}(\.[a-z0-9-]{2,64})*\.[a-z]{2,4}$");
    if (ER.test(email)){
    	return true;
    }
    else{
    	return false;
    }
}