?
Solved

Run-Time Error 94 - Invalid Use of Null

Posted on 2007-11-26
4
Medium Priority
?
1,471 Views
Last Modified: 2013-11-28
I created a text box (txtText) and pasted this function in the Control Source:
=GetTestType(Nz([cboTestType]). This text field is used only for display purposes.

When user selects an item from cboTestType, the item selected is displayed both in the combo and the textbox (txtTest).

Problem:
How do I correct this Run-Time error 94?
When user selects an item from a cboTestType, user gets: Run-Time error 94 - "Invalid use of Null"

.......on...
GetTestType = DLookup("TestType", "tblTest", "TestlID='" & myPID & "'")

...from the function below:

Public Function GetTestType(myPID As String) As String
If Len(myPID) < 2 Then
GetTestType = "" ' or whatever you want to dislpay in this case
Else
GetTestType = DLookup("TestType", "tblTest", "TestlID='" & myPID & "'")  '<<== Error line
End If
End Function
0
Comment
Question by:billcute
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 2
  • 2
4 Comments
 
LVL 46

Accepted Solution

by:
tbsgadi earned 2000 total points
ID: 20348918
Hi billcute,

GetTestType = nz(DLookup("TestType", "tblTest", "TestlID='" & myPID & "'"))

Good Luck!

Gary
0
 
LVL 4

Author Comment

by:billcute
ID: 20349016
tbsgadi:
Could you please provide an explanation why "nz" was placed before "DLookup"?
The same function worked for me in other texttype boxes.

Regards
Bill
0
 
LVL 4

Author Comment

by:billcute
ID: 20349119
tbsgadi:
Is there any way I can let you know of my future posts?
Regards
Bill
0
 
LVL 46

Expert Comment

by:tbsgadi
ID: 20349150
The nz turns nulls into "".
You probably didn't have nulls before.
If I'm online I'll see your posts
0

Featured Post

Three Reasons Why Backup is Strategic

Backup is strategic to your business because your data is strategic to your business. Without backup, your business will fail. This white paper explains why it is vital for you to design and immediately execute a backup strategy to protect 100 percent of your data.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

This article describes a method of delivering Word templates for use in merging Access data to Word documents, that requires no computer knowledge on the part of the recipient -- the templates are saved in table fields, and are extracted and install…
Code that checks the QuickBooks schema table for non-updateable fields and then disables those controls on a form so users don't try to update them.
With Microsoft Access, learn how to specify relationships between tables and set various options on the relationship. Add the tables: Create the relationship: Decide if you’re going to set referential integrity: Decide if you want cascade upda…
Add bar graphs to Access queries using Unicode block characters. Graphs appear on every record in the color you want. Give life to numbers. Hopes this gives you ideas on visualizing your data in new ways ~ Create a calculated field in a query: …
Suggested Courses

770 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question