Userform problem with Textboxes and IF Statement

Good day Guys

This is my first post as a member (and a guy that just discovered forms) so my humble apologies if I am doing it wrong.

So here goes:

Ive got a Userform (Tax_Year_Details) that asks the User to select TAX YEAR DATE from a combobox(works perfect) and then to type opening odometer from a textbox1 and closing odometer from textbox2 and then finally total Business Kilometer in textbox4. All of these three textboxes are defined as

Private Sub TextBox1_Change() 
Range("b8").Value = TextBox1
End sub 

Private Sub TextBox2_Change()
Range("b9").Value = TextBox2
End Sub

Private Sub TextBox4_Change()
Range("b14").Value = TextBox4
End Sub

Once proceeding to click on the OK button it need to do a few checks and if there are errors a msgbox should give a describtion.

.... example Textbox2 can not be less in value than textbox1. E.G Opening reading is 5000km (textbox1) and Closing reading 4000km(textbox2) = msgbox " Closing is less than opening - Re-enter"
and
....example textbox3 can not be more than the difference of textbox2-textbox1. E.G. Traveled 2000km this year but opening reading was on 1000km and closing reading was on 1400km, = msgbox " Kilometers traveled is greater than kilometers from Opening and Closing specified"

Private Sub Tax_year_OK_button_Click()
' First test that closing isnt less than opening
If Range("B9") < Range("B8") Then
MsgBox "CLOSING KILOMETERS IS LESS THAN OPENING KILOMTERS - Change Closing Kilometers"

TAX_Year_date.Show
 
'Second test if traveled in year for business is greater than Cell B9 - and cell B8
ElseIf Range("B14") < Range("B13") Then
MsgBox "TOTAL KILOMETERS TRAVELED IS LESS THAN BUSINESS KILOMTERS - Change Closing Kilometers"

TAX_Year_date.Show

'values are correctly entered proceed to next step
Range("b9").Value = TextBox2
End If

Unload Me

End Sub

Some times the values work sometimes it doesnt - Not sure why not. See attached pictures







Working Forum.png

Not Working Forum MSGBox.png

Not Working Forum MSGBox 2.png

Partly deleted while OP complied to Forum Rules.

Why not perform all tests (when OK-button pressed) before writing to Worksheet ?

Post example file with userform so we can test and adapt code.

I find that it is a lot easier to use one Macro to control all my textboxes.

Public Changeflag As Boolean

Private Sub TextBox1_Change()
Checksum
End Sub

Private Sub TextBox2_Change()
Checksum
End Sub

Private Sub TextBox4_Enter()
TextBox1.SetFocus
End Sub

Private Sub Checksum()
If Changeflag = True Or TextBox1 = "" Or TextBox2 = "" Then Exit Sub
Changeflag = True
If Not IsNumeric(TextBox1.Value) And TextBox1.Value <> "" Then TextBox1.Value = ""
If Not IsNumeric(TextBox2.Value) And TextBox2.Value <> "" Then TextBox2.Value = ""
If TextBox2 <> "" And TextBox1 > TextBox2 Then
MsgBox "CLOSING KILOMETERS IS LESS THAN OPENING KILOMTERS - Change Closing Kilometers"
Else
TextBox4.Value = TextBox2.Value - TextBox1.Value
End If
Changeflag = False
End Sub

This should do it.

You're welcome.