json format error

hello first post here im using thsi wonderfull plugin to use serverside data to my table but i get the error i check whit firebug and i got this results :

( ! ) Notice: Undefined index: sSearch in C:\wamp\www\busqueda.php on line 87
Call Stack
# Time Memory Function Location
1 0.0019 159208 {main}( ) ..\busqueda.php:0

( ! ) Notice: Undefined index: bSearchable_0 in C:\wamp\www\busqueda.php on line 104
Call Stack
# Time Memory Function Location
1 0.0019 159208 {main}( ) ..\busqueda.php:0

( ! ) Notice: Undefined index: bSearchable_1 in C:\wamp\www\busqueda.php on line 104
Call Stack
# Time Memory Function Location
1 0.0019 159208 {main}( ) ..\busqueda.php:0

( ! ) Notice: Undefined index: bSearchable_2 in C:\wamp\www\busqueda.php on line 104
Call Stack
# Time Memory Function Location
1 0.0019 159208 {main}( ) ..\busqueda.php:0

( ! ) Notice: Undefined index: bSearchable_3 in C:\wamp\www\busqueda.php on line 104
Call Stack
# Time Memory Function Location
1 0.0019 159208 {main}( ) ..\busqueda.php:0

( ! ) Notice: Undefined index: bSearchable_4 in C:\wamp\www\busqueda.php on line 104
Call Stack
# Time Memory Function Location
1 0.0019 159208 {main}( ) ..\busqueda.php:0

( ! ) Notice: Undefined index: bSearchable_5 in C:\wamp\www\busqueda.php on line 104
Call Stack
# Time Memory Function Location
1 0.0019 159208 {main}( ) ..\busqueda.php:0

( ! ) Notice: Undefined variable: sOrder in C:\wamp\www\busqueda.php on line 124
Call Stack
# Time Memory Function Location
1 0.0019 159208 {main}( ) ..\busqueda.php:0

( ! ) Notice: Undefined index: sEcho in C:\wamp\www\busqueda.php on line 158
Call Stack
# Time Memory Function Location
1 0.0019 159208 {main}( ) ..\busqueda.php:0
{"sEcho":0,"iTotalRecords":3,"iTotalDisplayRecords":3,"aaData":[["lol ","lololololl","2013-03-21","09:46:35.125","lololll ","20020200"],["jujujuj ","lololooloool","2013-03-21","09:46:51.843","\u00f1lololo ","201010101"],["uuuiuiii ","iuiuiiuiiiuii","2013-03-21","09:47:04.78","iuiuiiiui ","999"]]}

i didnt know you have to change those values since in the postgres example from here on server side data doesnt say anything what can i do to fix this i can see the json has data but i can show it properly, this is what i have on busqueda.php:

<?php
/*
* Script: DataTables server-side script for PHP and PostgreSQL
* Copyright: 2010 - Allan Jardine
* License: GPL v2 or BSD (3-point)
*/

/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
* Easy set variables
*/

/* Array of database columns which should be read and sent back to DataTables. Use a space where
* you want to insert a non-database field (for example a counter or static image)
*/
$aColumns = array( 'usuario', 'ip', 'fecha', 'hora', 'actividad','expediente_afectado' );

/* Indexed column (used for fast and accurate table cardinality) */
$sIndexColumn = "id";

/* DB table to use */
$sTable = "historial";

/* Database connection information */
$gaSql['user'] = "postgres";
$gaSql['password'] = "postgres";
$gaSql['db'] = "postgres";
$gaSql['server'] = "127.0.0.1";



/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
* If you just want to use the basic configuration for DataTables with PHP server-side, there is
* no need to edit below this line
*/

/*
* DB connection
*/
$gaSql['link'] = pg_connect(
" host=".$gaSql['server'].
" dbname=".$gaSql['db'].
" user=".$gaSql['user'].
" password=".$gaSql['password']
) or die('Could not connect: ' . pg_last_error());


/*
* Paging
*/
$sLimit = "";
if ( isset( $_GET['iDisplayStart'] ) && $_GET['iDisplayLength'] != '-1' )
{
$sLimit = "LIMIT ".intval( $_GET['iDisplayStart'] )." OFFSET ".
intval( $_GET['iDisplayLength'] );
}


/*
* Ordering
*/
if ( isset( $_GET['iSortCol_0'] ) )
{
$sOrder = "ORDER BY ";
for ( $i=0 ; $i<intval( $_GET['iSortingCols'] ) ; $i++ )
{
if ( $_GET[ 'bSortable_'.intval($_GET['iSortCol_'.$i]) ] == "true" )
{
$sOrder .= $aColumns[ intval( $_GET['iSortCol_'.$i] ) ]."
".($_GET['sSortDir_'.$i]==='asc' ? 'asc' : 'desc').", ";
}
}

$sOrder = substr_replace( $sOrder, "", -2 );
if ( $sOrder == "ORDER BY" )
{
$sOrder = "";
}
}


/*
* Filtering
* NOTE This assumes that the field that is being searched on is a string typed field (ie. one
* on which ILIKE can be used). Boolean fields etc will need a modification here.
*/
$sWhere = "";
if ( $_GET['sSearch'] != "" )
{
$sWhere = "WHERE (";
for ( $i=0 ; $i<count($aColumns) ; $i++ )
{
if ( $_GET['bSearchable_'.$i] == "true" )
{
$sWhere .= $aColumns[$i]." ILIKE '%".pg_escape_string( $_GET['sSearch'] )."%' OR ";
}
}
$sWhere = substr_replace( $sWhere, "", -3 );
$sWhere .= ")";
}

/* Individual column filtering */
for ( $i=0 ; $i<count($aColumns) ; $i++ )
{
if ( $_GET['bSearchable_'.$i] == "true" && $_GET['sSearch_'.$i] != '' )
{
if ( $sWhere == "" )
{
$sWhere = "WHERE ";
}
else
{
$sWhere .= " AND ";
}
$sWhere .= $aColumns[$i]." ILIKE '%".pg_escape_string($_GET['sSearch_'.$i])."%' ";
}
}


$sQuery = "
SELECT ".str_replace(" , ", " ", implode(", ", $aColumns))."
FROM $sTable
$sWhere
$sOrder
$sLimit
";
$rResult = pg_query( $gaSql['link'], $sQuery ) or die(pg_last_error());

$sQuery = "
SELECT $sIndexColumn
FROM $sTable
";
$rResultTotal = pg_query( $gaSql['link'], $sQuery ) or die(pg_last_error());
$iTotal = pg_num_rows($rResultTotal);
pg_free_result( $rResultTotal );

if ( $sWhere != "" )
{
$sQuery = "
SELECT $sIndexColumn
FROM $sTable
$sWhere
";
$rResultFilterTotal = pg_query( $gaSql['link'], $sQuery ) or die(pg_last_error());
$iFilteredTotal = pg_num_rows($rResultFilterTotal);
pg_free_result( $rResultFilterTotal );
}
else
{
$iFilteredTotal = $iTotal;
}



/*
* Output
*/
$output = array(
"sEcho" => intval($_GET['sEcho']),
"iTotalRecords" => $iTotal,
"iTotalDisplayRecords" => $iFilteredTotal,
"aaData" => array()
);

while ( $aRow = pg_fetch_array($rResult, null, PGSQL_ASSOC) )
{
$row = array();
for ( $i=0 ; $i<count($aColumns) ; $i++ )
{
if ( $aColumns[$i] == "version" )
{
/* Special output formatting for 'version' column */
$row[] = ($aRow[ $aColumns[$i] ]=="0") ? '-' : $aRow[ $aColumns[$i] ];
}
else if ( $aColumns[$i] != ' ' )
{
/* General output */
$row[] = $aRow[ $aColumns[$i] ];
}
}
$output['aaData'][] = $row;
}

echo json_encode( $output );

// Free resultset
pg_free_result( $rResult );

// Closing connection
pg_close( $gaSql['link'] );
?>

as you can see i only changed what the example sayed i dont know why i get those undefined variable errors thax in advance and sry for me being a noob at this

o and none of the fields on the db are boolean