Very Computer

I have a problem with an existing installation of an Oracle-Database
(Vers. 8) which we configurate
over the Microsoft ODBC Configurator on a Windows NT4 machine.

Theres no database installed on my machine so i try to access it with
an php-skript which reads as follows:
test_oracle.php:
<?
  $res = odbc_connect("anyhost","user","userpw");
  echo "$res";
?>

then the following error occurs:
----
Warning: SQL error: [Oracle][ODBC][Ora]ORA-12154: TNS: The service name
could not be solved.
, SQL state 08004 in SQLConnect in e:\htdocs\test_oracle.php on line 2
----

Disturbing is:
This small skript works with a machine which has a database installed
!!!
Also if we are not using ODBC the solving of server names is no problem
!!!

I have no clue what i can do to solve this problem ...
(im thinking this is just one of those problems which are very trivial
... but nevertheless annoying )

Any help would be fine

Greetings
F. Koller