You can use the "Compact and Repair" function in Access from ASP code. The following code is an example of
how this can be done. Note that when you decide to "Compact and Repair" your Access database, some
autonumbers can be changed. Access makes all autonumbers consecutive.
This code uses one database, but I'm sure the code can easily be changed so that the listbox displays, for
example, all the databases in one folder.

<%

Const Jet_Conn_Partial = "Provider=Microsoft.Jet.OLEDB.4.0; Data source="
Dim strDatabase, strFolder, strFileName

'#################################################
'# Edit the following two lines
'# Define the full path to where your database is
strFolder = "F:\InetPub\wwwroot\_db\"
'# Enter the name of the database
strDatabase = "YourAccessDatabase.mdb"
'# Stop editing here
'##################################################

Private Sub dbCompact(strDBFileName)
Dim SourceConn
Dim DestConn
Dim oJetEngine
Dim oFSO

SourceConn = Jet_Conn_Partial & strFolder & strDatabase
DestConn = Jet_Conn_Partial & strFolder & "Temp" & strDatabase

Set oFSO = Server.CreateObject("Scripting.FileSystemObject")
Set oJetEngine = Server.CreateObject("JRO.JetEngine")

With oFSO

If Not .FileExists(strFolder & strDatabase) Then
Response.Write ("Not Found: " & strFolder & strDatabase)
Stop
Else
If .FileExists(strFolder & "Temp" & strDatabase) Then
Response.Write ("Something went wrong last time " _
& "Deleting old database... Please try again")
.DeleteFile (strFolder & "Temp" & strDatabase)
End If
End If
End With

With oJetEngine
.CompactDatabase SourceConn, DestConn
End With

oFSO.DeleteFile strFolder & strDatabase
oFSO.MoveFile strFolder & "Temp" _
& strDatabase, strFolder& strDatabase

Set oFSO = Nothing
Set oJetEngine = Nothing
End Sub

Private Sub dbList()
Dim oFolders
Set oFolders = Server.CreateObject("Scripting.FileSystemObject")
Response.Write ("<Select Name=""DBFileName"">")
For Each Item In oFolders.GetFolder(strFolder).Files
If LCase(Right(Item, 4)) = ".mdb" Then
Response.Write ("<Option Value=""" & Replace(Item, strFolder, "") _
& """>" & Replace(Item, strFolder, "") & "</Option>")
End If
Next
Response.Write ("</Select>")

Set oFolders = Nothing
End Sub

%>
<%
' Compact database and tell the user the database is optimized
Select Case Request.form("cmd")
Case "Compact"
dbCompact Request.form("DBFileName")
Response.Write ("Database " & Request.form("DBFileName") & " is optimized.")
End Select
%>

<p><font size="4">Compact and repair database</font></p>
<form method="POST" action="">
<p><%dbList%><input type="submit" value="Compact" name="cmd"></p>
</form>