Enter text value into next availble cell in range if user selects correct answer

From Sheet1, user selects value from comboboxs, if users selection is correct then on another sheet in a specific range (H1:H8) a specific text is inputed into the first availble blank cell in that range. If all cells are filled then MsgBox"Please check your work for errors". I'm having trouble with three things.

1. How to stop loop if all cells are filled in the range.
2. How to use the code to prompt MsgBox if that range is full
3. How to enter the specificed TEXT values into the range on the worksheet. It just selects the cell.

I have included some sample code of what I'm using and three (out of 7) combobox examples. I just used combobox names vs cell to keep it clear. Thanks!

Dim wsNIGO As Worksheet
Dim wbBook As Workbook

Set wbBook = ActiveWorkbook
Set wsNIGO = wbBook.Worksheets("NIGO INFO")

If combobox1.Value = "No" Then
wsNigo.Range("C5").Select
Do Until ActiveCell.Value = ""
ActiveCell.Offset(1, 0).Value="Termination Date"
Loop

If combobox2.Value = "No" Then
wsNigo.Range("C5").Select
Do Until ActiveCell.Value = ""
ActiveCell.Offset(1, 0).Text="Forms"
Loop


If combobox3.Value = "New Bank" Then
wsNigo.Range("C5").Select
Do Until ActiveCell.Value = ""
ActiveCell.Offset(1, 0).Text="Vesting"
Loop



.....

Moderator Edit:

Welcome to the forum, jerbaldw.

Please notice that [CODE] tags have been added to your post. The forum rules require them so please keep that in mind and add them yourself whenever showing code in any of your future posts. To see instructions for applying them, click on the Forum Rules button at the top of the page and read Rule #3.
Thanks.