Do While Loop not giving me correct output string - ms-access

Question

I'm trying to assign a list of Names to a combobox control in Access VBA.
My problem is that the output string of names is not correct.
Here is my code:
Private Sub command186_click()
Dim firstName As String
Dim lastName As String
Dim rst As Object
Dim rowSourceText As String
Dim fullName As String
Set rst = CurrentDb.OpenRecordset("Pool_Contact")
Do While Not rst.EOF
firstName = rst("FName").Value
lastName = rst("LName").Value
fullName = firstName + " " + lastName
rst.MoveNext
Loop
Forms(FrmDaysAvailable).Controls("Combo202").rowSource = fullName
Debug.Print fullName
End Sub
I know that the error is somewhere inside of my loop, where the variable fullName is written over by the second result.
how can I fix this loop to produce a string that looks like fullName , fullName, fullName ...
Thanks for all your help

Answer 1

This can be a lot simpler:
Forms(FrmDaysAvailable).Controls("Combo202").rowSource = _
"SELECT ID, FName & ' ' & LName FROM Pool_Contact"
Or
Forms!FrmDaysAvailable.Combo202.rowSource = _
"SELECT ID, FName & ' ' & LName FROM Pool_Contact"
Or
Me.Combo202.rowSource = "SELECT ID, FName & ' ' & LName FROM Pool_Contact"
Furthermore, use & not + to concatenate. Plus (+) will give you problems with nulls.

Answer 2

You must add each item to the ComboBox, instead you are only adding the last one
Do While Not rst.EOF
firstName = rst("FName").Value
lastName = rst("LName").Value
fullName = firstName & " " & lastName
Me!Combo202.AddItem(fullName)
rst.MoveNext
Loop
Also you should declare rst as DAO.Recordset not as object. (You might have to add a reference to the DAO dll).
Optionally you can assign a table or a query directly to the row source of the ComboBox and drop the loop completely
Me!Combo202.RowSource = "Pool_Contact"
But you can do that in the form designer and do not need to do it in VBA at all. If you need to refresh the contents of the ComboBox you can simply write
Me!Combo202.Requery
Note: I assume that Forms(FrmDaysAvailable) is the current form. In that case you can simply address it through Me. Further, the Controls collection is the default property of a form. Forms(FrmDaysAvailable).Controls("Combo202") can be simplyfied to Me("Combo202") or even to Me!Combo202 with the VBA collection access operator !.
I also suggest you to give your ComboBox (and other controls) meaningful names like cboFullName. This makes the code more readable. I usually make a query corresponding to the ComboBox with the same name prefixed with "q": qcboFullName and assign this to the RowSource of the combo in the properties window. A query has the advantage over a table that you can apply a "ORDER BY" and select exactly the columns needed for the ComboBox.
Typically you would have a hidden ID column (enter 0 in the column width property) as result of the user selection and a string column for display.
SELECT PersonID, firstName & ' ' & lastName AS Display
FROM tblPerson
ORDER BY firstName, lastName