FORM.screenshot is Undefined

Hi. I am trying to upload a file from a form. In my CFFORM, i have the following input:

<cfinput type="file" name="screenshot" width="250" value="" />

The page I submit to has this line at the top:

<cfif FORM.screenshot NEQ "">
       <!--- first actually upload the file --->
       <cffile action="upload"
                 filefield="screenshot"
                 destination="D:\temp\"
                 nameconflict="makeunique">
        <!--- now create a temporary holder for the attachment later on --->
        <cfset screenshot_local_file = "D:\temp\#file.serverfile#">
</cfif>

However, when I upload the page, I get FORM.screenshot is undefined. All other form fields work fine.

Thanks for the help. 🙂