I have recently upgraded to php version 4.2.1 and before that everything was working fine, but now evertime i use a variable which is defined by user input on a seperate html form or gets its value from a query string it get this error:

Notice: Undefined variable: room in c:\program files\apache\apache\htdocs\php\index.php on line 10

Notice: Undefined variable: room in c:\program files\apache\apache\htdocs\php\index.php on line 11


even though i reach it like this, http://aptiva/php/index.php?room=Aptiva
it still comes out with the same error

If you are still unclear what i am trying to say (im not the best at explaining things) then check out the below exapmle of a code that would give me this error:

I would type in the url for this script while including the query string of ?username=hi&password=hito
which would leed to this script,

<?
echo"
The username is <? echo $username; ?>
The Password is <? echo $password; ?>
"
?>

and i would get the error of :

Notice: Undefined variable: username in c:\program files\apache\apache\htdocs\php\index.php on line 3

Notice: Undefined variable: password in c:\program files\apache\apache\htdocs\php\index.php on line 4

Can anyone help me here?

PS. i am a twelve year old so be descriptive
also i am using apache as my server software