Installing PHP on XP/IIS 5.1

What's up people. I'm trying to install PHP 4.2.3 on XP with IIS 5.1, and in following install.txt, I've run into a snag when I get to the part where it says:

Quote:

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Under 'Home Directory' click on the 'Configuration' button. Add a new entry to the Application Mappings. Use the path to the php4isapi.dll as the Executable, supply .php as the extension, leave Method exclusions blank, and check Script engine checkbox.

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It's all fine and dandy (other than the fact that there's no 'Method exclusion' field or checkbox, whichever it happens to be), but when I'm done filling everything out and checking/unchecking all the checkboxes that need to be checked/unchecked, the 'OK' button is grayed out, denying me my right to have fun with PHP.

Now comes the question. Anyone know why the 'OK' button is grayed out? Thanks in advance for any help, and I'm gonna go play some AA:O now. Laters.

Daftness