var lnk = 'register.php?n=' + $('#fname').value + '&f=' + $('#pnumb').value + '&m=' + $('#elecm').value + '&l=' + $('#uname').value + '&p=' + $('#pword').value + '&p2=' + $('#pconf').value;
        $.post(lnk, function (data) { //Do something with data }

<?php
//databse info
$servername = "localhost";
$username = "root";
$password = "";
$dbname = "phptest";
//Getting values from link
$comname = $_GET['n'];
$phone = $_GET['f'];
$mail = $_GET['m'];
$uname = $_GET['l'];
$pass = $_GET['p'];
$conf = $_GET['p2'];
//Checking if any value is left empty
if (empty($comname)) {
    echo '1';
}
elseif (empty($phone)) {
    echo '2';
}
elseif (empty($mail)) {
    echo '3';
}
elseif (empty($uname)) {
    echo '4';
}
elseif (empty($pass)) {
    echo '5';
}
elseif (empty($conf)) {
    echo '6';
}