Simple query wont run properly - PC setting?

[Big Pat]

Hi,

I'm working from a colleague's office today, using her PC to set up what should be a very simple database. My table includes 5 fields, RequiredHours_Mon, RequiredHours_Tue, etc. Data type - Number; Field size - Double; Decimal places - Auto.

I have entered a couple of test records and now I want to get the total weekly hours for each record. The data shows up in the query, but the calculated field just returns a blank. This is what I'm using:
WeeklyTotal: [RequiredHours_Mon]+[RequiredHours_Tue]+[RequiredHours_Wed]+[RequiredHours_Thu]+[RequiredHours_Fri]

This should be so simple. Am I missing something obvious? All I can think is that there's a setting somewhere is Access that's stopping it, a bit like you can turn off automatic calculations in Excel, but I don't know where to look.

It's Windows XP Professional, with Access 2003 SP3.

Any ideas? Thanks!

 

[Big Pat]

Further information...

A query using text fields runs fine i.e. Name: [Surname] & ", " & [Forename] returns a list of staff in the required format.

So (I think) it must be something to do withthe data type, field size etc. of the numeric fields in my other table. Still can't figure it out!

 

[gemma-the-husky]

maybe plussing nulls?

I would check that, first.

 

[Big Pat]

All this time and I never knew you coudn't add Nulls! Makes sense when I stop and think about it for a minute.

Figured out how to use the Nz() function - eventually!!! I thought I could put it round the whole expression, but it appears you have to apply it to each field.

Thanks so much!