What is the value of a blank field in a table?

In my program I have a field that sums up a couple date/time fileds. If one
of the time fields dont have a value in there when i try to sum it in my
query it will give me an error.(#ERROR). How can i get around this problem?

If a field has no entry, its value is Null.
You should be able to sum a field that contains Nulls, e.g.:
=DSum("MyField", "MyTable")

If you try to add fields horizontally across a record, then you must use
Nz() to substitute zero for null, e.g.:
=Nz([Field1], 0) + Nz([Field2], 0) + ...

--
Allen Browne - Microsoft MVP. Perth, Western Australia.
Tips for Access users - http://allenbrowne.com/tips.html
Reply to group, rather than allenbrowne at mvps dot org.

"William" wrote in message
...
In my program I have a field that sums up a couple date/time fileds. If
one
of the time fields dont have a value in there when i try to sum it in my
query it will give me an error.(#ERROR). How can i get around this
problem?