Form validates data before submitting - vba

Question

I'm a beginner when it comes to VB and i'm having a bit of trouble developing a form. What i'm trying to achieve is for the form, on click,to:
Validate four text boxes and nine combo boxes, ensuring they all have values before being submitted to an MS Excel sheet
If there are null fields, a message box telling the user "Text box(es) and/or drop down box(es) must contain data" (or something to that effect) should appear
Assuming all fields have values, the workbook must be unprotected
Data must then be input into the Excel sheet (each form submission equals one row of data, which must not be overwritten by subsequent entries).
The workbook must be protected again
The form must be hidden once all actions are complete.
Here's my code so far. I'm sure its very simplistic and can be made more efficient -- any suggestions welcome. Thank you in advance for your help.
Private Sub CommandButton1_Click()
Sheet2.Unprotect
Dim LastRow As Object
Set LastRow = Sheet2.Range("a65536").End(xlUp)
LastRow.Offset(1, 0).Value = ExpRecDrop.Text
Set LastRow = Sheet2.Range("b65536").End(xlUp)
LastRow.Offset(1, 0).Value = CPName.Text
Set LastRow = Sheet2.Range("c65536").End(xlUp)
LastRow.Offset(1, 0).Value = ConEntDrop.Text
Set LastRow = Sheet2.Range("d65536").End(xlUp)
LastRow.Offset(1, 0).Value = ResTypDrop.Text
Set LastRow = Sheet2.Range("e65536").End(xlUp)
LastRow.Offset(1, 0).Value = LangDrop.Text
Set LastRow = Sheet2.Range("f65536").End(xlUp)
LastRow.Offset(1, 0).Value = WritDrop.Text
Set LastRow = Sheet2.Range("g65536").End(xlUp)
LastRow.Offset(1, 0).Value = OwnerDrop.Text
Set LastRow = Sheet2.Range("i65536").End(xlUp)
LastRow.Offset(1, 0).Value = BiRiDrop.Text
Set LastRow = Sheet2.Range("j65536").End(xlUp)
LastRow.Offset(1, 0).Value = ERTextBox.Text
Set LastRow = Sheet2.Range("k65536").End(xlUp)
LastRow.Offset(1, 0).Value = DueDatDrop.Text
Set LastRow = Sheet2.Range("l65536").End(xlUp)
LastRow.Offset(1, 0).Value = SubTypDrop.Text
Set LastRow = Sheet2.Range("o65536").End(xlUp)
LastRow.Offset(1, 0).Value = CommText.Text
Sheet2.Protect DrawingObjects:=True, Contents:=True, Scenarios:=True
Me.Hide
MsgBox "One record written to the 2014 tab"
End Sub
This is my first post so please let me know if you need any more information.

Answer 1

You could try this. I've created a Boolean (True/False) variable to determine if the update should happen, if any of your controls is blank it will change to false and skip the update. The other change I've made is instead of repeatedly working out the next available cell is to work out the next free row number once and use that as a reference to the row to populate.
Private Sub CommandButton1_Click()
Dim LastRow As Long
Dim isOk As Boolean
sheet2.Unprotect
' Create boolean variable as true and check controls for data, if any data missing, change to false
isOk = True
If ExpRecDrop.Text = "" Then isOk = False
If CPName.Text = "" Then isOk = False
If ConEntDrop.Text = "" Then isOk = False
If ResTypDrop.Text = "" Then isOk = False
If LangDrop.Text = "" Then isOk = False
If WritDrop.Text = "" Then isOk = False
If OwnerDrop.Text = "" Then isOk = False
If BiRiDrop.Text = "" Then isOk = False
If ERTextBox.Text = "" Then isOk = False
If DueDatDrop.Text = "" Then isOk = False
If SubTypDrop.Text = "" Then isOk = False
If CommText.Text = "" Then isOk = False
' if boolean value is still true, update the sheet, else display error message
If Not isOk Then
With sheet2
' get number of the next free row
Set LastRow = .Range("a65536").End(xlUp).Row + 1
' Populate the sheet
.Cells(LastRow, 1).Value = ExpRecDrop.Text
.Cells(LastRow, 2).Value = CPName.Text
.Cells(LastRow, 3).Value = ConEntDrop.Text
.Cells(LastRow, 4).Value = ResTypDrop.Text
.Cells(LastRow, 5).Value = LangDrop.Text
.Cells(LastRow, 6).Value = WritDrop.Text
.Cells(LastRow, 7).Value = OwnerDrop.Text
.Cells(LastRow, 8).Value = BiRiDrop.Text
.Cells(LastRow, 9).Value = ERTextBox.Text
.Cells(LastRow, 10).Value = DueDatDrop.Text
.Cells(LastRow, 11).Value = SubTypDrop.Text
.Cells(LastRow, 12).Value = CommText.Text
.Protect DrawingObjects:=True, Contents:=True, Scenarios:=True
End With
' Hide userform and confirm
Me.Hide
MsgBox "One record written to the 2014 tab"
Else
' Error message
MsgBox "Some data missing"
End If
End Sub