Stumped...JOIN with a DatePart on a field name...

OK...yes I am new to SQL Server 2005...I am moving T-SQL from a 7.0 server to a 2005 server and I am struggling with joins. The following is supposed to retrieve all records from the WebProxyHours table...which simply contains the numbers 1-24 and report the ClientUserName and PageHits for those in hours in which data exists in the table WebProxyLog. I have failed to make any progress so far...my code simply displays data only for those hours in which there is data. I use this data to display a 24 hour graph...showing all of the hours of the day even though they may not have had any activity.

If anyone could steer me in the right direction I would appreciate it. Thanks in advance.

T-SQL Code:

SELECT WebProxyHours.msp_hour, WebProxyLog.ClientUserName, Count(WebProxyLog.DestHost) PageHits
FROM WebProxyHours LEFT OUTER JOIN WebProxyLog on DatePart(hour, WebProxyLog.LogTime) = WebProxyHours.msp_hour
WHERE ( DatePart(month, WebProxyLog.LogDate) = DatePart(month, GetDate()) ) AND ( DatePart(day, WebProxyLog.LogDate) = DatePart(day, GetDate()) ) AND ( DatePart(year, WebProxyLog.LogDate) = DatePart(year, GetDate()) ) AND ( Left(WebProxyLog.ClientUserName,3) = 'FLM' ) AND ( WebProxyLog.mimetype = 'text/html' )
GROUP BY WebProxyHours.msp_hour, WebProxyLog.ClientUserName
ORDER BY WebProxyHours.msp_hour ASC