notice that this is a simple example! Not a full solution.
You need to make a form, and have a while cycle, the $res is a result from your table:
while ( $one_row = mysql_fetch_assoc( $res ) )
{
/* echo out the other values from the table */
/* create a checkbox with array variable name*/
echo '<td><div align="center"><input type="checkbox" name="del[]" value="' . $one_row["id"] . '"></div></td>';
}
You then close the form...
And in del.php:
if ( isset( $_POST["del"] ) )
{
$delete_ids = array_map( "intval" , $_POST["del"] );
$sql = sprintf( "DELETE FROM table WHERE id IN (%s)" , implode( ",", $delete_ids ) );
mysql_query( $sql ) or die( mysql_error() . $sql );
echo mysql_affected_rows() . " row(s) were deleted";
exit();
}