php访问oracle问题...

Question

<?php
echo "hello world!";
if($c=OCILogon("syst","cjw","chenjiawei"))
{
  echo "Successfully connected to oracle.\n";
}
?>http://localhost:8080/index.php
Warning: ocilogon() [function.ocilogon]: OCIEnvNlsCreate() failed. There is something wrong with your system - please check that PATH includes the directory with Oracle Instant Client libraries in E:\php\www\index.php on line 17