PHP script is not inserting into the database.

<?php 
    include 'mod2_config.php';
    include 'mod2_opendb.php';



    $employeeid= (isset($_POST['employeeid'])    ? $_POST['employeeid']   : '');
     $managementid= (isset($_POST['managementid'])    ? $_POST['managementid']   : '');
                             $fname= (isset($_POST['first_name'])    ? $_POST['first_name']   : '');
                             $lname= (isset($_POST['last_name'])    ? $_POST['last_name']   : '');
                             $age= (isset($_POST['age'])    ? $_POST['age']   : '');
                             $employment_period= (isset($_POST['employment_period'])    ? $_POST['employment_period']   : ''); 


$sql= " INSERT INTO employees (employeeid, managementid, first_name, last_name, age, employement_period)
                        VALUES ('$employeeid ','$managementid', $fname','$lname','$age', '$employment_period')";
$result = mysqli_query($con, $sql);

$sql= " SELECT employeeid, managementid, first_name, last_name, age, employment_period from employees WHERE employeeid = $employeeid LIMIT 1";

$result = mysqli_query($con, $sql);

if (mysqli_num_rows($result) > 0) {
    // output data of each row
    while($row = mysqli_fetch_assoc($result)) {
                echo "<b>Record successfully inserted:</b><br>";
                echo "<b>EmployeeID: " . $row["employeeid"]. "</b><br>";
                echo "<b>ManagementID: " . $row["managementid"]. "</b><br>";
        echo "<b>Name: " . $row["first_name"]. " " . $row["last_name"]. "</b><br>";
                echo "<b>Age: " . $row["age"]. "</b><br>";
                echo "<b>Employment Period In Months: " . $row["employment_period"]. "</b><br>";
    }
} else {
    echo "Sorry there are no matches! Please check your entry and try again.";
}

mysqli_close($con);

?>