十万火急,请各位老大看看如何解决

zj_rose

单位做网站,已经搭好oracle ,nt2000 server ,用PHP 连接不上，语句如下:
<?
$dbconn=OCILogon("jhlss","jhlss123","(DESCRIPTION=(ADDRESS=(PROTOCOL =TCP)(HOST=202.107.180.173)(PORT = 1521))(CONNECT_DATA =(SID=ORCL)))";
if($dbconn!=false)
{
echo "连接成功";
if(OCILogOff($dbconn)==true)
{
echo "关闭连接成功!";//=这里有问题
}
}
else
{
echo "连接失败";
}
?>;

错误的结果是:
Fatal error: Call to undefined function: ocilogon() in D:\apache2\Apache2\htdocs\123.php on line 2

ORACLE 是8.0.5 的

那位大大看看,时间很紧啊,这边先谢了