I have an error in sending data using textbox by POST to data base ERROR IS"NOTICE:UNDEFINED INDEX ON LINE"

How can I solve this problem ?

This is my code :

```
<?php
error_reporting(0);
$con = mysql_connect("localhost","root","");

mysql_select_db("hello", $con);

$result = mysql_query("SELECT Max(id) as id from `aoa` WHERE 1");

$row = mysql_fetch_array($result);
  {

    echo $row['id'];
  }

 if($v=="")
{
 $v=1000;

}

$v=$row['id'];

$v=$v+1;
$id=$v;

$sql="INSERT INTO aoa(id,name,clss)
VALUES
('$id','$_POST[name]','$_POST[clss]')";
var_dump($sql);
if (!mysql_query($sql,$con))
  {
   die('Data InsertionError: ' . mysql_error());
  }
echo "Successfully Registered";

mysql_close($con);
?>

```

(AND THIS IS MY ERROR FILE)

```

Notice: C:\wamp\www\Register.php line 31 - Undefined index:  clss
Notice: C:\wamp\www\Register.php line 31 - Undefined index:  name
Notice: C:\wamp\www\Register.php line 17 - Undefined variable: v

```