jquery ui slider post to mysql

Hello Im trying to update the value of the slider to mysql, i keep getting "Notice: Undefined index... on line 2 ", I am sure my error is ridiculous but I cant seem to find it, since it worked fine on normal input fields.

    <script src="http://code.jquery.com/jquery-1.10.2.js"></script>
    <script src="http://code.jquery.com/ui/1.11.0/jquery-ui.js"></script>
    <link rel="stylesheet" href="/resources/demos/style.css">
     <script>
     $(function() {
         $( "#slider-vertical" ).slider({
             range: "min",
             min: 0,
             max: 100,
             value: 60,
             slide: function( event, ui ) {
                 $( "#amount" ).val( ui.value );
             }
    });
         $( "#amount" ).val( $( "#slider-vertical" ).slider( "value" ) );
     });
     </script>
 </head>
 <body>
 <p>
 <form action="update.php" method="post">
     <label for="amount">Volume:</label>

     <input type="text" id="amount" name="amount" style="border:0; color:#f6931f; font-weight:bold;" />
     <input type="submit">

     </form>

This is my update.php:

<?php
$temp= $_POST['raise'];
echo $temp;
$host=""; // Host name 
$username=""; // Mysql username 
$password=""; // Mysql password 
$db_name=""; // Database name 
$tbl_name=""; // Table name 

$dbc = mysqli_connect("$host", "$username", "$password", "$db_name")or die("cannot connect");
$sql="UPDATE $tbl_name SET raise='$temp' WHERE id= 1";

?>

After you fixed your variable to $post['amount'], your seeing the value because update.php line 3 echos out the value:

echo $temp;

Line 11 doesn't escape the value with $dbc->real_escape_string() (bad idea!), and finally, to actually update the database you're missing this at the end:

$dbc->query($sql);