I have two list boxes on a form (List0) and (List1)

For List0 I have the following code that works fine.

Private Sub Cmdok_Click()
' Declare variables
Dim db As DAO.Database
Dim qdf As DAO.QueryDef
Dim varItem As Variant
Dim strCriteria As String
Dim strSQL As String
' Get the database and stored query
Set db = CurrentDb()
Set qdf = db.QueryDefs("qryMultiSelect")
' Loop through the selected items in the list box and build a text string
For Each varItem In Me!List0.ItemsSelected
strCriteria = strCriteria & ",'" & Me!List0.ItemData(varItem) & "'"
Next varItem
' Check that user selected something
If Len(strCriteria) = 0 Then
MsgBox "You did not select anything from the list" _
, vbExclamation, "Nothing to find!"
Exit Sub
End If
' Remove the leading comma from the string
strCriteria = Right(strCriteria, Len(strCriteria) - 1)
' Build the new SQL statement incorporating the string
strSQL = "SELECT * FROM tbleportsmaster " & _
"WHERE tbleportsmaster.rdcdestination IN(" & strCriteria & ");"
' Apply the new SQL statement to the query
qdf.SQL = strSQL
' Open the query
DoCmd.OpenQuery "qryMultiSelect"
' Empty the memory
Set db = Nothing
Set qdf = Nothing
End Sub

__________________________________________________ _
For List1 - I have the code below that works fine.


Private Sub Comd1_Click()
' Declare variables
Dim db As DAO.Database
Dim qdf As DAO.QueryDef
Dim varItem As Variant
Dim strCriteria As String
Dim strSQL As String
' Get the database and stored query
Set db = CurrentDb()
Set qdf = db.QueryDefs("qryMultiSelect2")
' Loop through the selected items in the list box and build a text string
For Each varItem In Me!List1.ItemsSelected
strCriteria = strCriteria & ",'" & Me!List1.ItemData(varItem) & "'"
Next varItem
' Check that user selected something
If Len(strCriteria) = 0 Then
MsgBox "You did not select anything from the list" _
, vbExclamation, "Nothing to find!"
Exit Sub
End If
' Remove the leading comma from the string
strCriteria = Right(strCriteria, Len(strCriteria) - 1)
' Build the new SQL statement incorporating the string
strSQL = "SELECT * FROM tbleportsmaster " & _
"WHERE tbleportsmaster.posupplier IN(" & strCriteria & ");"
' Apply the new SQL statement to the query
qdf.SQL = strSQL
' Open the query
DoCmd.OpenQuery "qryMultiSelect2"
' Empty the memory
Set db = Nothing
Set qdf = Nothing
End Sub
__________________________________________

Problem 1:
These list boxes are on a Form that also has two text boxes (txtstartdate) and (txtenddate)for date criteria that needs to be entered also when I run the above queries. I do not know how to prompt that in the events above and need some help.

Problem 2:
The user may select from one list box or both and I am not sure how to incorporate that into these queries.

I am very new with VBA and can only work well with clear instructions. Would appreaciate some help. Thanks.