code not working

[shaz123]

I am trying to lookup the clinder barcode inputed into Stringy1, i occordance with the latest inout for that cylinder barcode number. I the cylnder number is already delivered a message below should appear, can anyone see why this code is not wkring

StrSQ4 = DLookup("[D Status]", "tbl_Delupdate", "[Cylinder Barcode Label]='" & Stringy1 & "' AND [Date of D Status]=#" _
& DMax("[Date of D Status]", "tbl_Delupdate", "[Cylinder Barcode Label] = '" & Stringy1 & "'") & "#")
If Trim(StrSQ4 & "") = "Delivered" Then
MsgBox "Barcode Number is already delivered. Please re-check and try again", vbCritical, "Barcode Number

 

[mp9]

What sort of failure is this? Do you get the wrong data returned? Do you get an error message? Does your code fall over at a certain point and, if so, at what point?

Without this information your problem is difficult to diagnose.

 

[shaz123]

Sowi aobut not explaning myself properly, it was bringing a null value. But what ive dun is looked up the date sepratly and it is now bringing up the correct value.

maxdate = DMax("[Date of D Status]", "tbl_Delupdate", "[Cylinder Barcode Label] = '" & Stringy1 & "'")

However i am now getting a error mesage saying
"Invalid use of Null"
when i the date of D status is equal to null.

The coding i have used is

  Stringy1 = InputBox("Please Enter/Scan the Cylinder Barcode Label You Wish to Deliver")
   
    If StrPtr(Stringy1) <> 0 Then
       strSQL = "SELECT * FROM [tbl_Delupdate] WHERE [Cylinder Barcode Label] = '" & Stringy1 & "' "
       StrSQ3 = DLookup("[Cylinder Barcode Label]", "tbl_Delupdate", "[Cylinder Barcode Label] ='" & Stringy1 & "'")
      StrSQ4 = "SELECT [D Status] From [tbl_Delupdate] WHERE [Cylinder Barcode Label] = '" & Stringy1 & "' "
    
    If StrSQ4 <> "" Then
        maxdate = DMax("[Date of D Status]", "tbl_Delupdate", "[Cylinder Barcode Label] = '" & Stringy1 & "'")
        MsgBox "Barcode Number is already delivered. Please re-check and try again", vbCritical, "Barcode Number"
    Else
    If StrSQ4 = "" Then
       Stringy2 = InputBox("The Cylinder/Cylinders Will Be Delivered For The Specified Date Below:-", "Spec Gas 2006, (DD / MM / YY)", Me!Text20 & "")
       Set rs = db.OpenRecordset("SELECT * From tbl_Delupdate Where [Cylinder Barcode Label] = '" & Stringy1 & "'")
   
   If rs![Cylinder Barcode Label] = Stringy1 Then
         rs.Edit
         rs![D Status] = "Delivered"
         rs![Date of D Status] = Stringy2
         rs![CustomerReturn/LindePickup] = Stringy3
         rs.Update
      
    MsgBox "Selected items have been marked as delivered for date " & Stringy2, vbInformation, "Items Changed Successfully"

  End If
  End If
  End If
  End If

If the Date oo status is empty i wanted it to able to edit the record