SQLSRV PHP removing selected record

There are not many tutorials in the web about Mssql using sqlsrv driver, so I followed similar tutorials with MySQL and using sqlsrv API I was converting my code. So far all works, I can add records with popup form etc.

Now I'm trying to delete multiple records with checkbox. I tried all the tutorials I was able to find but it still does not work.

There is no effect after selecting checkbox and pressing delete apart question from onDelete script which asking me if I like to delete records.

I have two php files - SQLTest.php and delete.php.

Code from SQLTest.php

<h1>SQL Testing</h1>
<h1>Component Group Modifications</h1>

<table class="table_general">
<tbody>

<tr>
  <th>ID</th>
  <th colspan="2">MODIFICATIONS</th>
  <th colspan="3">APPLICABLE WORKSHEET</th> 
  <th>Delete</th>
</tr>

<?php
$serverName = "THOMAS-PC\SQLEXPRESS";
$connectionInfo = array( "Database"=>"test");
$conn = sqlsrv_connect( $serverName, $connectionInfo);

if( $conn ) 
{
     echo "Connected to Database !";
}
else
{
     echo "Opps - something went wrong !";
     die( print_r( sqlsrv_errors(), true));
}

$tsql = "SELECT * FROM dbo.modIndex";
$query = sqlsrv_query($conn, $tsql);
if ($query === false){  exit("<pre>".print_r(sqlsrv_errors(), true));

}
while ($row = sqlsrv_fetch_array($query))
{  
?>
  <tr>
    <td><?php echo $row["recordID"];?></td>
    <td><?php echo $row["first"];?></td>
    <td><?php echo $row["second"];?></td>
    <td><?php echo $row["third"];?></td>
    <td><?php echo $row["fourth"];?></td>
    <td><?php echo $row["fifth"];?></td>
    <td><input type="checkbox" name="chkDel[]" value="<?php echo $row["recordID"];?>"></td>
  </tr>
<?php
}
sqlsrv_free_stmt($query);
?>

</tbody>
<input type="button" value="Delete Selected Records" action="delete.php" method="post" onclick="return onDelete();"/>
</table>

</section>
</section>

Code from delete.php

<?php

$serverName = "THOMAS-PC\SQLEXPRESS";
$connectionInfo = array( "Database"=>"test");
$conn = sqlsrv_connect( $serverName, $connectionInfo);

if( $conn === false )
{
     echo "<script>alert('Opps - something went wrong !');</script>";
     die( print_r( sqlsrv_errors(), true));
}
for($i = 0; $i < count($_POST["chkDel"]);$i++)
{
    if($_POST["chkDel"][$i] != "")

        {
            $tsql = "DELETE FROM dbo.modIndex ";
            $tsql = "WHERE recordID = '".$_POST["chkDel"][$i]."'  "; 
            $query = sqlsrv_query($conn, $tsql);
        }
}
    echo "Record Deleted.";

sqlsrv_free_stmt( $tsql);
sqlsrv_close( $conn);

?>

Short onDelate function:

<script language="JavaScript">
    function onDelete()
    {
        if(confirm('Do you want to delete ?')==true)
        {
            return true;
        }
        else
        {
            return false;
        }
    }
</script>

And my SQL details:

database -> test -> table : dbo.modIndex recordID - first - second - third - fourth - fifth

Thank you in advance for your help.

<?php
if ( !isset($_POST["chkDel"]) || !is_array($_POST["chkDel"]) ) {
    die('missing or wrong parameter "chkDel"');
}

$serverName = "THOMAS-PC\SQLEXPRESS";
$connectionInfo = array( "Database"=>"test");
$conn = sqlsrv_connect( $serverName, $connectionInfo);
if( $conn === false ) {
    echo "<script>alert('Opps - something went wrong !');</script>";
    die( print_r( sqlsrv_errors(), true) );
}

$query = 'DELETE FROM dbo.modIndex WHERE ID=?';
$stmt = sqlsrv_prepare($conn, $query, array(&$id));
if( !$stmt ) {
    die( print_r( sqlsrv_errors(), true) );
}

foreach( $_POST["chkDel"] as $id ) {
    if( !sqlsrv_execute( $stmt ) ) {
        die( print_r( sqlsrv_errors(), true) );
    }
}