Two TextBox one Answer VBA6 - excel

Question

In my UserForm, I have two Text Box. I want to be able to FIND by either Text Box, but use only one or the other. If both are empty I want a MSGBOX telling user to enter information. I can make my code do either/or text box entry but not two textbox where the user skips TextBox1 or does not entry anything.
Here is my code.....
Private Sub OkayCommandButton_Click()
Worksheets("Parts List").Select
Application.ScreenUpdating = False
Range("A2").Select
PN = PartNumber.Value
KN = KanbanNumber.Value
If PartNumber = vbNullString Then
MsgBox "Please enter a Part Number"
PartNumber.SetFocus
Else
Cells.find(What:=PN, After:=Range("A2"), LookIn:=xlFormulas, _
LookAt:=xlPart, SearchOrder:=xlByRows, SearchDirection:=xlNext, _
MatchCase:=False, SearchFormat:=False).Activate
End If
If Kanban = vbNullString Then
MsgBox "Please enter a Kanban Number"
PartNumber.SetFocus
Else
Cells.find(What:=KN, After:=Range("A1"), LookIn:=xlFormulas, _
LookAt:=xlPart, SearchOrder:=xlByRows, SearchDirection:=xlNext, _
MatchCase:=False, SearchFormat:=False).Activate
End If
PartInformation.Caption = _
"Part Number" & vbTab & ActiveCell & vbCrLf & _
"Kanban" & vbTab & vbTab & ActiveCell.Offset(0, 45) & vbCrLf & _
"Part Name" & vbTab & ActiveCell.Offset(0, 1) & vbCrLf & _
"Supplier" & vbTab & vbTab & ActiveCell.Offset(0, 2) & vbCrLf & _
"Next Process" & vbTab & ActiveCell.Offset(0, 3) & vbCrLf & _
"Qty in Tote" & vbTab & ActiveCell.Offset(0, 44) & vbCrLf & _
"PC Location" & vbTab & ActiveCell.Offset(0, 46)
PartInformation1.Caption = "Line " & ActiveCell.Offset(0, -1)
End Sub

Answer 1

You could check first if both TextBox-Elements are empty and then give a message to the user. If that check fails either one or both Text-Box-Elements contain text. You have a conflict there, since you only want to use one TextBox-Element for the search if both textboxes contain a search string. In this case you have to give one of the textboxes priority (the first one you check then wins):
This is only a snippet of your text:
PN = PartNumber.Value
KN = KanbanNumber.Value
If ((PartNumber = vbNullString) And (KanbanNumber = vbNullstring)) Then
' Both textboxes are empty, message box opened and focus to part number
MsgBox "Please enter a Part Number or Kanban Number"
PartNumber.SetFocus
Else
' One or more textboxes contain a search string
If Not (PartNumber = vbNullString) Then
'Part number is given, run search
Cells.find(What:=PN, After:=Range("A2"), LookIn:=xlFormulas, _
LookAt:=xlPart, SearchOrder:=xlByRows, SearchDirection:=xlNext, _
MatchCase:=False, SearchFormat:=False).Activate
Else
' Part Number is not given
' Since we checked that at least one textbox contains text
' the Kanban Number must be set if Part Number has not been set
Cells.find(What:=KN, After:=Range("A1"), LookIn:=xlFormulas, _
LookAt:=xlPart, SearchOrder:=xlByRows, SearchDirection:=xlNext, _
MatchCase:=False, SearchFormat:=False).Activate
End If
End If