it is connecting to the database but is not inserting values please help me with inserting the form values into the table registered `
if (isset($_POST["submit"])) {
    $dbconnect = new mysqli('localhost','root','','tas');
    if ($dbconnect) {
        echo "connected to database";
    }
    else{
        echo "did not connect";
    }
    $fname = $_POST["fname"];
    $lname = $_POST["lname"];
    $cert = $_POST["certificate"];
    $sex =  $_POST["sex"];
    $mobile = $_POST["mobile"];
    $email  = $_POST["email"];
    $institution =  $_POST["institution"];
    $session    =   $_POST["session"];
    $media  =   $_POST["media"];
    $insert ="INSERT INTO registered(firstmame,lastname,certificatename,sex,mobile,email,institution,session,media)
     VALUES ($fname,$lname,$cert,$sex,$mobile,$email,$institution,$session,$media)" ;
     if (!$insert) {
        echo "</br>error id not insert";
     }
     else{
        echo"<br/> success";
     }
}
?>`
 
     
    