dsum and dlookup help

[Kozbot]

I have this code

Private Sub Time_AfterUpdate()
If DSum("Time", "Timelog", "criteria = '" & Forms![Timelog Entry Form]!LotNo & "'") <> _
DLookup("RunTime", "Production and Material Usage Table", "criteria = '" & Forms![Timelog Entry Form]!LotNo & "'") + _
DLookup("Downtime", "Production and Material Usage Table", "criteria = '" & Forms![Timelog Entry Form]!LotNo & "'") Then
MsgBox "Time reported on Timelog and Production report do not match", vbOKOnly
End If
End Sub

I am getting run time error 2471. The expression you entered as a query parameter produced this error 'criteria'

What is wrong here? Also is my syntax correct when comparing the dsum value to the sum of the two dlookup values?

 

[pbaldy]

I'm guessing "criteria" is not the name of a field in the table, which it needs to be.

 

[Kozbot]

I'm guessing "criteria" is not the name of a field in the table, which it needs to be.

I'm retarded, thanks!

 

[pbaldy]

Happy to help!

 

[Kozbot]

I am now having a problem with the msgbox appearing even if the comparison is equal. Anyone have any insight?

 

[spikepl]

You should not have a field called Time because that is a reserved word: http://support.microsoft.com/kb/286335

What unit is Time measured in? if it is the DateTime field, then it is a double, and arithmetic operations on such numbers have a limited precision.

1+1=2
but, for example
1.5 + 1.5 =2.99999999999999

so to compare two double values you could

double a, double b

If abs(a-b)< some very small number Then
a is considered equal b

 

[Kozbot]

You should not have a field called Time because that is a reserved word: http://support.microsoft.com/kb/286335

What unit is Time measured in? if it is the DateTime field, then it is a double, and arithmetic operations on such numbers have a limited precision.

1+1=2
but, for example
1.5 + 1.5 =2.99999999999999

so to compare two double values you could

double a, double b

If abs(a-b)< some very small number Then
a is considered equal b

Time is a regular decimal numeric field. It is a record of total time in hours that time entry covers. I am trying to add up those entries for a lot number and compare them to another table where the runtime and downtime are recorded (for that same lot number) and look for discrepancies.