Service Record Form Null Check not working as expected (1 Viewer)

[JMongi]

I have a button that is going to use DateDiff to calculate service call times.

I put a basic check in to verify that there are values in the two fields but it doesn't seem to be working as intended. I fear this is something super basic, please help.

Private Sub btnEndTime_Click()
Dim dt As Date

'Set the value to the current time
Me.EndTime = Now()

Debug.Print Me.StartTime

'Update the site time text box
If Me.StartTime <> Null Then
    MsgBox "Updating"
    dt = DateDiff("n", Me.EndTime, Me.StartTime)
    Me.txtSiteTime = dt
Else
   'Nothing
End If

End Sub

In stepping through the code, even when I can see that there are two date values in the fields and debug.print confirms that, the code portion of the IF statemetn won't run.

 

[theDBguy]

That's because you can't compare Null to anything else, because it's unknown. Try using the IsNull() function instead.

 

[JMongi]

I think I've made this same mistake about 3 times every time I go to do something like this. I wonder where I got that idea in my head....

 

[JMongi]

Private Sub btnEndTime_Click()
Dim dt As Date

'Set the value to the current time
Me.EndTime = Now()

'Update the site time text box
If IsNull(Me.StartTime) = False Then
    dt = DateDiff("n", Me.EndTime, Me.StartTime)
    Me.txtSiteTime = dt
Else
   'Nothing
End If

End Sub

Took out the debugging parts, works great! Thanks!

Now to find the thread where it talks about formatting the difference into hh:mm:ss

 

[theDBguy]

Glad to hear you got it sorted out. Good luck!