Multi Select Box's

I am looking to see if anyone can help i have been able to get the multi select function part of my form working but i need another filter in the query for a date but it keeps deleting this part of the query everytime i run the report what i need to be able to do is get all jobs against a specific leadcraft that are in the past and also 31 days into the future.

Paul

here is the sql so far, thanks to those who helped already.

Private Sub preview_Click()
Dim db As DAO.Database
Dim qdf As DAO.QueryDef
Dim varItem As Variant
Dim strCriteria As String
Dim strSQL As String
Set db = CurrentDb()
Set qdf = db.QueryDefs("FAelecplan")
If Me!Leadcraftlist.ItemsSelected.Count > 0 Then
For Each varItem In Me!Leadcraftlist.ItemsSelected
strCriteria = strCriteria & "MAXIMO_V_WORKORDERS_FA.LEADCRAFT = " & Chr(34) _
& Me!Leadcraftlist.ItemData(varItem) & Chr(34) & "OR "
Next varItem
strCriteria = Left(strCriteria, Len(strCriteria) - 3)
Else
strCriteria = "MAXIMO_V_WORKORDERS_FA.LEADCRAFT Like '*'"
End If
strSQL = "SELECT * FROM MAXIMO_V_WORKORDERS_FA " & _
"WHERE " & strCriteria & ";"
qdf.SQL = strSQL
Dim stDocName As String
stDocName = "elecplan"
DoCmd.OpenReport stDocName, acPreview
On Error GoTo Err_preview_Click
Exit_preview_Click:
Exit Sub

Err_preview_Click:
MsgBox Err.Description
Resume Exit_preview_Click
End Sub