PHP - Code Will Not Sum Negative Number In Mysql Field? :( Pls Help!)

|  id          | int(4)       | NO   | PRI | NULL    | auto_increment |
| user_id     | int(4)       | NO   |     | NULL    |                |
| recipient   | varchar(30)  | NO   |     | NULL    |                |
| subject     | varchar(25)  | YES  |     | NULL    |                |
| cc_email    | varchar(30)  | YES  |     | NULL    |                |
| reply       | varchar(20)  | YES  |     | NULL    |                |
| location    | varchar(50)  | YES  |     | NULL    |                |
| stationery  | varchar(40)  | YES  |     | NULL    |                |
| ink_color   | varchar(12)  | YES  |     | NULL    |                |
| fontchosen  | varchar(30)  | YES  |     | NULL    |                |
| message     | varchar(500) | NO   |     | NULL    |                |
| attachment  | varchar(40)  | YES  |     | NULL    |                |
| messageDate | datetime     | YES  |     | NULL    |        

            $params = array(                 
               ':user_id' => $userid,                 
               ':recipient' => $this->message_vars['recipient'],                 
               ':subject' => $this->message_vars['subject'],                 
               ':cc_email' => $this->message_vars['cc_email'],                 
               ':reply' => $this->message_vars['reply'],                 
               ':location' => $this->message_vars['location'],                 
               ':stationery' => $this->message_vars['stationery'],                 
               ':ink_color' => $this->message_vars['ink_color'],                 
               ':fontchosen' => $this->message_vars['fontchosen'],                 
               ':message' => $messageInput,                 
               ':attachment' => $this->message_vars['attachment'],                 
               ':messageDate' => $date             );

$sql = "INSERT INTO messages (user_id,recipient, subject, cc_email, reply, location,stationery, ink_color, fontchosen, message,attachment) VALUES( $userid, :recipient, :subject, :cc_email, :reply, :location, :stationery, :ink_color, :fontchosen, $messageInput, :attachment, $date);";

And lastly, here is how I am calling it:
            $dbh = parent::$dbh;             
           $dbh->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_WARNING);              
           if (empty($dbh))    return false;             
                  $stmt = $dbh->prepare($sql);             
                 $stmt->execute($params) or die(print_r($stmt->errorInfo(), true));              
           if (!$stmt) {    print_r($dbh->errorInfo());              }

<?php

include("includes/model/database_searches/see_readings.php");
include("includes/model/database_searches/see_watchings.php");

function one_more_visit_to_topic($user_id,$topic_id)
{
    global $db;
    $request_string='UPDATE forum_topic '.
    'SET topic_vu = topic_vu + 1 WHERE topic_id = :topic';
    $query=$db->prepare($request_string);
    $query->bindValue(':topic',$topic_id,PDO::PARAM_INT);
    $query->execute();
    $query->CloseCursor();
    // Remember that topic has been read by user
    if(!(see_if_user_has_read_topic($user_id,$topic_id))) {
        $request_string='INSERT INTO forum_read (fr_topic_id,fr_user_id) '.
        'VALUES (:topic,:user)';
        $query=$db->prepare($request_string);
        $query->bindValue(':topic',$topic_id,PDO::PARAM_INT);  
        $query->bindValue(':user',$user_id,PDO::PARAM_INT);  
        $query->execute();
        $query->CloseCursor();
    }
    // If user has already received a warning by mail,
    // the "alert" value needs to be toggled in the fw_watch table
    if(see_if_user_has_been_warned($user_id,$topic_id)) {
        $request_string='UPDATE forum_read SET fw_alert = :alt '.
        'WHERE fw_topic_id = :topic AND fw_user_id= :user)';
        $query=$db->prepare($request_string);
        $query->bindValue(':topic',$topic_id,PDO::PARAM_INT);  
        $query->bindValue(':user',$user_id,PDO::PARAM_INT);
        $one=(int)1;
        $query->bindValue(':alt',$one,PDO::PARAM_INT);  
        $query->execute();
        $query->CloseCursor();
    }
    return;
}


?>

Hi,

 I want to make the phone number in the below code as clickable. Below is the code php and mysql code I used.

    <?php  
    $connect = mysqli_connect('localhost', 'root', '1234', 'contact');  
    $query ='SELECT * FROM tbl_employee ORDER BY ID DESC';  
    $result = mysqli_query($connect, $query); 
    ?>

<table id="employee_data" class="table table-striped table-bordered">
                <thead>  
                <tr>  
                <td>Name</td>  
                <td>Location</td>  
                <td>Department</td>  
                <td>Phone Number</td>  
                </tr>  
                </thead>  
                          <?php  
                          while($row = mysqli_fetch_array($result))  
                          {  
                               echo '  
                               <tr>  
                                    <td>'.$row["name"].'</td>  
                                    <td>'.$row["location"].'</td>    
                                    <td>'.$row["department"].'</td>  
                                    <td>'.$row['phone_number'].'</td>
                  
                               </tr>  
                               ';  
                          }  
                          ?>  
</table>