Problem deleting in table

Hi, i have a problem with deleting data from a table.
First problem is that the data doesnt show in the table.
second the delete doesnt work.

here is the code:

<?php
$host="localhost"; // Host name 
$username="root"; // Mysql username 
$password=""; // Mysql password 
$db_name="people"; // Database name 
$tbl_name="usersinfo"; // Table name 

// Connect to server and select databse.
mysql_connect("$host", "$username", "$password")or die("cannot connect"); 
mysql_select_db("$db_name")or die("cannot select DB");

$sql="SELECT * FROM $tbl_name";
$result=mysql_query($sql);

$count=mysql_num_rows($result);
?>


<table width="400" border="0" cellspacing="1" cellpadding="0">
<tr>
<td><form name="form1" method="post" action="">
<table width="400" border="0" cellpadding="3" cellspacing="1" bgcolor="#CCCCCC">
<tr>
<td bgcolor="#FFFFFF"> </td>

</tr>
<tr>
<td align="center" bgcolor="#FFFFFF">#</td>
<td align="center" bgcolor="#FFFFFF"><strong>username</strong></td>
<td align="center" bgcolor="#FFFFFF"><strong>Lastname</strong></td>
<td align="center" bgcolor="#FFFFFF"><strong>firstname</strong></td>
<td align="center" bgcolor="#FFFFFF"><strong>MI</strong></td>
<td align="center" bgcolor="#FFFFFF"><strong>Company</strong></td>
<td align="center" bgcolor="#FFFFFF"><strong>position</strong></td>
<td align="center" bgcolor="#FFFFFF"><strong>department</strong></td>
</tr>

<?php
while($rows=mysql_fetch_array($result)){
?>

<tr>
<td align="center" bgcolor="#FFFFFF"><input name="checkbox[]" type="checkbox" id="checkbox[]" value="<? echo $rows['id']; ?>"></td>
<td bgcolor="#FFFFFF"><? echo $rows['USERNAME']; ?></td>
<td bgcolor="#FFFFFF"><? echo $rows['LASTNAME']; ?></td>
<td bgcolor="#FFFFFF"><? echo $rows['FIRSTNAME']; ?></td>
<td bgcolor="#FFFFFF"><? echo $rows['MI']; ?></td>
<td bgcolor="#FFFFFF"><? echo $rows['COMPANY']; ?></td>
<td bgcolor="#FFFFFF"><? echo $rows['POSITION']; ?></td>
<td bgcolor="#FFFFFF"><? echo $rows['DEPARTMENT']; ?></td>

</tr>

<?php
}
?>

<tr>
<td colspan="5" align="center" bgcolor="#FFFFFF"><input name="delete" type="submit" id="delete" value="Delete"></td>
</tr>

<?php

// Check if delete button active, start this 

if($delete){
for($i=0;$i<$count;$i++){
$del_id = $checkbox[$i];
$sql = "DELETE FROM $tbl_name WHERE id='$del_id'";
$result = mysql_query($sql);
}
// if successful redirect to delete_multiple.php 
if($result){
echo "<meta http-equiv=\"refresh\" content=\"0;URL=deletesam.php\">";
}
}
mysql_close();
?>

</table>
</form>
</td>
</tr>
</table>

an error is also shown saying: UNDEFINED VARIABLE ON LINE 66 ..
Please help. Thanks in advance.