PHP获取通知问题

调用“index.php”?pconta=1&pdatainicial=01-01-2000&pdatafinal=31-12-2000“我收到以下通知:

[08-Oct-2009 17:30:35] PHP Notice:  Undefined index: pConta in index.php on line 1
[08-Oct-2009 17:30:35] PHP Notice:  Undefined index: pDataInicial in index.php on line 2
[08-Oct-2009 17:30:35] PHP Notice:  Undefined index: pDataFinal in index.php on line 3

index.php源:

<?php
    $conta = $_GET['pConta'];
    $dtIni = $_GET['pDataInicial'];
    $dtFin = $_GET['pDataFinal'];
?>

“var_dump($_get)”显示如下:

array(3) { ["pConta"]=> string(1) "1" ["pDataInicial"]=> string(10) "01-01-2000" ["pDataFinal"]=> string(10) "31-12-2000" }

而$conta、$dtini和$dtfin的值除外。