Data validation in user form - excel

Question

I have a userform for entering the receiving data by the storekeepers, I want to set some mandatory fields for filling in. They are the username, part number and stored location of received file.
I am using the data of my "ref" worksheet for adding items to my combo boxes. and I forced combo box to don't accept any item out of that list. (by using field property "matchrequired" to true).
I have 4 command buttons, done for saving and closing, "add item" for adding a new item to current release note, new release note, which clear the R/N data and would ask for it again, and finally close, which closes the form.
My question is how can I force VBA to check is there any data in the "USER", "P/N" and "Location", and if at least these three field have data, then data entry be possible.
I also want to the code to be able for checking the entry of QTY field and just accepts number (between 1 and 5000 for instance).
Everything is ok with DONE button, but for the two ("add item" and "new release note") stupid errors returns. after msg box showing up the data clears, the combo's items will lost or returns error and so...
I am using "addcmbo" for adding items to combo controls. (Just for user when I am putting that here, the value duplicates in the combo index, and also after message box, the items of this control remains).
If you find any "not good practice" approaches, let me know please.
Sub addcmbo()
Application.ScreenUpdating = False
Sheet2.Activate
' A/C data update
For i = 2 To WorksheetFunction.CountA(Range("b:b"))
If Sheets("Ref").Cells(i, 2) <> "" Then
RCVNG.cmbac.AddItem (Cells(i, 2))
End If
Next
' W/B data update
For i = 2 To WorksheetFunction.CountA(Range("h:h"))
If Sheets("Ref").Cells(i, 8) <> "" Then
RCVNG.Cmbwb.AddItem (Cells(i, 8))
End If
Next
' w/C data update
For i = 2 To WorksheetFunction.CountA(Range("i:i"))
If Sheets("Ref").Cells(i, 9) <> "" Then
RCVNG.Cmbwc.AddItem (Cells(i, 9))
End If
Next
' P/# data update
For i = 2 To WorksheetFunction.CountA(Range("j:j"))
If Sheets("Ref").Cells(i, 10) <> "" Then
RCVNG.Cmbpn.AddItem (Cells(i, 10))
End If
Next
Sheet1.Activate
Application.ScreenUpdating = True
End Sub
Private Sub btnCncl_Click()
Unload Me
End Sub
Private Sub btnadditem_Click()
' Form fields Clear
cmbac.Clear
Cmbwb.Clear
Cmbwc.Clear
Cmbpn.Clear
' cmbac.Value = ""
' Cmbwb.Value = ""
' Cmbwc.Value = ""
' Cmbpn.Value = ""
Txtqty.Value = ""
txtSN.Value = ""
Txtloc.Value = ""
cmnt.Value = ""
' Data entry sufficiency check
If cmbuser = "" Or Cmbpn = "" Or Txtloc = "" Then
MsgBox "Please Fill Required Fields " & Chr(10) & " * User" & Chr(10) & " * Part #" & Chr(10) & " * Location" & Chr(10) & " before Save!"
Call addcmbo
Else:
' Data Entry
Sheet1.Activate
Dim oNewRow As ListRow
ActiveSheet.Cells(1, 3).Select
Set oNewRow = Selection.ListObject.ListRows.Add(AlwaysInsert:=True)
oNewRow.Range.Cells(1, 6).Value = DTPicker.Value
oNewRow.Range.Cells(1, 7).Value = txtrn.Value
oNewRow.Range.Cells(1, 14).Value = cmbuser.Value
oNewRow.Range.Cells(1, 8).Value = cmbac.Value
oNewRow.Range.Cells(1, 10).Value = Cmbwb.Value
oNewRow.Range.Cells(1, 9).Value = Cmbwc.Value
oNewRow.Range.Cells(1, 11).Value = Cmbpn.Value
oNewRow.Range.Cells(1, 12).Value = Txtqty.Value
oNewRow.Range.Cells(1, 13).Value = txtSN.Value
oNewRow.Range.Cells(1, 15).Value = Txtloc.Value
oNewRow.Range.Cells(1, 16).Value = cmnt.Value
End If
End Sub
Private Sub btndone_Click()
' Data entry sufficiency check
If cmbuser = "" Or Cmbpn = "" Or Txtloc = "" Then
MsgBox "Please Fill Required Fields " & Chr(10) & " * User" & Chr(10) & " * Part #" & Chr(10) & " * Location" & Chr(10) & " before Save!"
Else:
' Data Entry
Sheet1.Activate
ActiveSheet.Cells(1, 3).Select
Set oNewRow = Selection.ListObject.ListRows.Add(AlwaysInsert:=True)
oNewRow.Range.Cells(1, 6).Value = DTPicker.Value
oNewRow.Range.Cells(1, 7).Value = txtrn.Value
oNewRow.Range.Cells(1, 14).Value = cmbuser.Value
oNewRow.Range.Cells(1, 8).Value = cmbac.Value
oNewRow.Range.Cells(1, 10).Value = Cmbwb.Value
oNewRow.Range.Cells(1, 9).Value = Cmbwc.Value
oNewRow.Range.Cells(1, 11).Value = Cmbpn.Value
oNewRow.Range.Cells(1, 12).Value = Txtqty.Value
oNewRow.Range.Cells(1, 13).Value = txtSN.Value
oNewRow.Range.Cells(1, 15).Value = Txtloc.Value
oNewRow.Range.Cells(1, 16).Value = cmnt.Value
Unload Me
End If
End Sub
Private Sub btnnewrn_Click()
Dim oNewRow As ListRow
' Form fields Clear
txtrn.Value = ""
cmbac.Clear
Cmbwb.Clear
Cmbwc.Clear
Cmbpn.Clear
cmbac.Value = ""
Cmbwb.Value = ""
Cmbwc.Value = ""
Cmbpn.Value = ""
Txtqty.Value = ""
txtSN.Value = ""
Txtloc.Value = ""
cmnt.Value = ""
' Data entry sufficiency check
If cmbuser = "" Or Cmbpn = "" Or Txtloc = "" Then
MsgBox "Please Fill Required Fields " & Chr(10) & " * User" & Chr(10) & " * Part #" & Chr(10) & " * Location" & Chr(10) & " before Save!"
Call addcmbo
Else:
' Data Entry
Sheet1.Activate
ActiveSheet.Cells(1, 3).Select
Set oNewRow = Selection.ListObject.ListRows.Add(AlwaysInsert:=True)
oNewRow.Range.Cells(1, 6).Value = DTPicker.Value
oNewRow.Range.Cells(1, 7).Value = txtrn.Value
oNewRow.Range.Cells(1, 14).Value = cmbuser.Value
oNewRow.Range.Cells(1, 8).Value = cmbac.Value
oNewRow.Range.Cells(1, 10).Value = Cmbwb.Value
oNewRow.Range.Cells(1, 9).Value = Cmbwc.Value
oNewRow.Range.Cells(1, 11).Value = Cmbpn.Value
oNewRow.Range.Cells(1, 12).Value = Txtqty.Value
oNewRow.Range.Cells(1, 13).Value = txtSN.Value
oNewRow.Range.Cells(1, 15).Value = Txtloc.Value
oNewRow.Range.Cells(1, 16).Value = cmnt.Value
End If
End Sub
Private Sub lblpn_DblClick(ByVal Cancel As MSForms.ReturnBoolean)
Dim pn As String
Application.ScreenUpdating = False
Sheet2.Activate
emptyRow = WorksheetFunction.CountA(Range("j:j")) + 1
pn = inputbox("Type In new ''P/#'' please", "Add NEW P/#")
Cells(emptyRow, 10).Value = pn
RCVNG.Cmbpn.AddItem pn
End Sub
Private Sub lblTeam_DblClick(ByVal Cancel As MSForms.ReturnBoolean)
Dim t As String
Application.ScreenUpdating = False
Sheet2.Activate
emptyRow = WorksheetFunction.CountA(Range("c:c")) + 1
t = inputbox("Type type Your Name Please", "Add name of NEW or Missing team member")
Cells(emptyRow, 3).Value = t
RCVNG.cmbuser.AddItem t
End Sub
Private Sub UserForm_Initialize()
Application.ScreenUpdating = False
Sheet2.Activate
DTPicker.SetFocus
DTPicker.Value = Date
' empty fields
shipreceive.Value = ""
txtrn.Value = ""
cmbuser.Clear
cmbac.Clear
Cmbwb.Clear
Cmbwc.Clear
Cmbpn.Clear
Txtqty.Value = ""
txtSN.Value = ""
Txtloc.Value = ""
cmnt.Value = ""
' Combo fields add item
Call addcmbo
' User data update
Application.ScreenUpdating = False
Sheet2.Activate
For i = 2 To WorksheetFunction.CountA(Range("c:c"))
If Sheets("Ref").Cells(i, 3) <> "" Then
RCVNG.cmbuser.AddItem (Cells(i, 3))
End If
Next
Sheet1.Activate
Application.ScreenUpdating = True
End Sub
Thanks a lot, I will appreciate your help