Use this code as an On Click – event procedure for your command button. You will need to use your command button name and your report name.
Private Sub CommandButtonName_Click()
On Error GoTo Err_CommandButtonName_Click
Dim stDocName As String
stDocName = "YourReportName"
DoCmd.OpenReport stDocName, acPreview
Exit_CommandButtonName_Click:
Exit Sub
Err_CommandButtonName_Click:
MsgBox Err.Description
Resume Exit_CommandButtonName_Click
End Sub
Hope this helps