use a multi-select listbox to filter a report

I recently tried to use code for "Use a multi-select list box to
filter a report" from Allen Browne in my database. I was able to add
the code and adapt it to my needs, however I am getting an error.

I click Ok and the report opens.

I look in the design view and the filter is there but the IN equals
"" [it is blank, the values are not in there]

The description that appears on the report, which is the strDescrip is
correct. I can see the descriptions of the items I have selected but
the criteria is not picking them up.

I am using Access 2002 - 2003. My criteria is a text field.

Table name is: Tbl_Interns
Criteria field is: Work State Location
Report Name Is: Rpt_WorkingStates

On my report I added a text field called: TxtReportCriteria
And in the control source, I added:=[Report].[OpenArgs]
Here is a sample of the code I am using.
Private Sub CmdPreview_Click[]
On Error GoTo Err_Handler
'Purpose: Open the report filtered to the items selected in the
list box.
'Author: Allen J Browne, 2004. //allenbrowne.com
Dim varItem As Variant 'Selected items
Dim strWhere As String 'String to use as WhereCondition
Dim strDescrip As String 'Description of WhereCondition
Dim lngLen As Long 'Length of string
Dim strDelim As String 'Delimiter for this field type.
Dim strDoc As String 'Name of report to open.

strDelim = """" 'Delimiter appropriate to field type.
See note 1.
strDoc = "Rpt_WorkingStates"

'Loop through the ItemsSelected in the list box.
With Me.LstCategory
For Each varItem In .ItemsSelected
If Not IsNull[varItem] Then
'Build up the filter from the bound column [hidden].
strWhere = strWhere & strDelim & .ItemData[varItem] &
strDelim & ","
'Build up the description from the text in the visible
column. See note 2.
strDescrip = strDescrip & """" & .Column[1, varItem] &
""", "
End If
Next
End With

'Remove trailing comma. Add field name, IN operator, and brackets.
lngLen = Len[strWhere] - 1
If lngLen 0 Then
strWhere = "Tbl_Interns.[Work State Location]IN [" & Left$
[strWhere, lngLen] & "]"
lngLen = Len[strDescrip] - 2
If lngLen 0 Then
strDescrip = "Selected Work States: " & Left$[strDescrip,
lngLen]
End If
End If

'Report will not filter if open, so close it. For Access 97, see
note 3.
If CurrentProject.AllReports[strDoc].IsLoaded Then
DoCmd.Close acReport, strDoc
End If

'Omit the last argument for Access 2000 and earlier. See note 4.
DoCmd.OpenReport strDoc, acViewPreview, WhereCondition:=strWhere,
OpenArgs:=strDescrip

Exit_Handler:
Exit Sub

Err_Handler:
If Err.Number