asp catch errors

On Error Resume Next
Set rstResult=cnnDb.Execute(strSQL)
If cnnDb.Errors.Count=0 Then
   ' show the result
Else
   ' handle the error
End If
On Error Goto 0
-----------------------

On Error Resume Next
Set xmlDoc = CreateObject("MSXML.DOMDocument")
    if Err.number<>0 then
 MsgBox "failed to create MSXML,error:" & err.description
        Set xmlDoc = nothing
 On Error GoTo 0
    else
        MsgBox "success to create MSXML object"
    end if