Problem with Array

[Anon]

I have a form that posts these fields:

<input class=input name=product_price["500NO"] size=3 value="150.00">
<input class=input name=product_rental["500NO"] size=3 value="39.99">
...
<input class=input name=product_price["500BO"] size=3 value="0.00">
<input class=input name=product_rental["500BO"] size=3 value="39.99">
... and lots more...

When I try to retieve these values in the posted page, I can't.

So, a variable called product_price["500NO"] has been set, but when I
echo $product_price["500NO"];
it returns nothing. WHY??

If I phpinfo() I see this:
HTTP_POST_VARS["product_price"]
Array
(
["500NO"] => 150.00
["500BO"] => 120.00
["1000NO"] => 750.00

... and lots more...

[Anon]

Leave the quotes out of the html part, like this:

<input type=text name=test[500AC]>

...

print $test["500AC"];