Hello Excel champions!

While the block of code below works however, it looks quiet an eye-sore as there are so many iterations that I believe can be simplified with nested loops. While I am currently fighting my intimidation to Looping statements, can you guys shed a light on me as to how this can be reduced into its simplest form? I will be going to study your solutions and hopefully get past my fear in looping.

Thanks in advance.


Private Sub CommandButton2_Click()

With Me
  
    If .ComboBox1.Value = "" Then
        MsgBox "Please select Tube Diameter and Thickness first", vbCritical
        Exit Sub
    ElseIf .TextBox1.Value <> "" And .TextBox2.Value = "" And .TextBox3.Value = "" And .TextBox4.Value = "" _
            And .TextBox5.Value = "" And .TextBox6.Value = "" And .TextBox7.Value = "" And .TextBox8.Value = "" _
            And .TextBox9.Value = "" And .TextBox10.Value = "" And .TextBox11.Value = "" And .TextBox12.Value = "" Then
                Call str_tube_less_equal_90
                GoTo Drawing
                Exit Sub
    ElseIf .TextBox1.Value <> "" And .TextBox2.Value <> "" And .TextBox3.Value = "" And .TextBox4.Value = "" _
            And .TextBox5.Value = "" And .TextBox6.Value <= 90 And .TextBox7.Value = "" And .TextBox8.Value = "" _
            And .TextBox9.Value = "" Then
                If .TextBox12.Value <= 90 Or .TextBox12.Value = "" Then
                    Call sb_tube_less_equal_90
                    GoTo Drawing
                    Exit Sub
                Else
                    GoTo Errmessage
                    Exit Sub
                End If
    ElseIf .TextBox1.Value <> "" And .TextBox2.Value <> "" And .TextBox3.Value <> "" And .TextBox4.Value = "" _
            And .TextBox5.Value = "" And .TextBox6.Value <= 90 And .TextBox7.Value <= 90 And .TextBox8.Value = "" _
            And .TextBox9.Value = "" Then
                If .TextBox12.Value <= 90 Or .TextBox12.Value = "" Then
                    Call db_tube_less_equal_90
                    GoTo Drawing
                    Exit Sub
                Else
                    GoTo Errmessage
                    Exit Sub
                End If
    ElseIf .TextBox1.Value <> "" And .TextBox2.Value <> "" And .TextBox3.Value <> "" And .TextBox4.Value <> "" _
            And .TextBox5.Value = "" And .TextBox6.Value <= 90 And .TextBox7.Value <= 90 And .TextBox8.Value <= 90 _
            And .TextBox9.Value = "" Then
                If .TextBox12.Value <= 90 Or .TextBox12.Value = "" Then
                    Call tb_tube_less_equal_90
                    GoTo Drawing
                    Exit Sub
                Else
                    GoTo Errmessage
                    Exit Sub
                End If
    ElseIf .TextBox1.Value <> "" And .TextBox2.Value <> "" And .TextBox3.Value <> "" And .TextBox4.Value <> "" _
            And .TextBox5.Value <> "" And .TextBox6.Value <= 90 And .TextBox7.Value <= 90 And .TextBox8.Value <= 90 _
            And .TextBox9.Value <= 90 Then
                If .TextBox12.Value <= 90 Or .TextBox12.Value = "" Then
                    Call qb_tube_less_equal_90
                    GoTo Drawing
                    Exit Sub
                Else
                    GoTo Errmessage
                    Exit Sub
                End If
    ElseIf .TextBox1.Value = "" And .TextBox2.Value = "" And .TextBox3.Value = "" And .TextBox4.Value = "" _
            And .TextBox5.Value = "" And .TextBox6.Value = "" And .TextBox7.Value = "" And .TextBox8.Value = "" _
            And .TextBox9.Value = "" And .TextBox10.Value <> "" And .TextBox11.Value <> "" And .TextBox12.Value <= 90 Then
                Call sb_tube_less_equal_90
                GoTo Drawing
                Exit Sub
    End If
   
   
Errmessage:
    MsgBox "Error occurs due to any of the following instances:" & vbNewLine & vbNewLine & _
            "-  One of the angles indicated in upper section is greater than 90" & Chr(176) & vbNewLine & _
            "-  The angle indicated in lower section is greater than 90" & Chr(176) & vbNewLine & _
            "-  Required fields are left empty" & vbNewLine & _
            "-  Some text boxes are expecting inputs" & vbNewLine & vbNewLine & _
            "Please go back and check your entries.", vbCritical, "Expecting inputs from required fields"
    For i = 13 To 15
        .Controls("TextBox" & i).Text = ""
    Next i
    

Drawing:
    For i = 0 To 8
        If .Controls("TextBox" & i + 1).Text = "" Then
            .Controls("Label" & i + 20).Caption = "L" & i + 1
                If i + 20 >= 25 Then
                    .Controls("Label" & i + 20).Caption = Chr$(92 + i)
                End If
        Else
            .Controls("Label" & i + 20).Caption = .Controls("TextBox" & i + 1).Text
        End If
    Next i
       
End With

End Sub