Len(VLookup()) Error

I know there are instances where the Vlookup() will not find a value. When it does not I want it to pop up secondary list. The problem is the Vlookup() errors out when it can't find a value.

    Dim iopcert As Variant, hospital As Variant, miss_hosp As String, inp_form As Worksheet
    Dim ocd1 As Worksheet, hosp_form As NoOpcert, lngindex As Long
    
    iopcert = Application.InputBox(prompt:="Enter the hospitals opcert #" & i, Title:="OPCERT" & i, Left:=300, Top:=250, Type:=1)
    Set ocd1 = ActiveWorkbook.Sheets("OPCERT")
    
    If Len(Application.WorksheetFunction.VLookup(iopcert, ocd1.Range("A1:C187"), 2, False)) = 0 Then
        Set hosp_form = NoOpcert
        With hosp_form
            .Show
            miss_hosp = .hosp_list.Value
        End With
        Unload hosp_form
        Set hosp_form = Nothing
        If lngindex = -1 Then
            MsgBox "Nothing was selected!"
        Else
        End If
    Else
        hospital = Application.WorksheetFunction.VLookup(opcert, ocd1.Range("A1:C187"), 2, False)
    End If

Any idea how to get around this?

    If IsError(Application.WorksheetFunction.VLookup(iopcert, ocd1.Range("A1:C187"), 2, False)) = True Then

didn't work either. I still get a run-time error: 1004 Unable to get the Vlookup() property of the worksheet function class.

If IsError(Application.WorksheetFunction.VLookup(iopcert, ocd1.Range("A1:C187"), 2, False)) = 2042 Then

Since it's an N/A error the above code should work, but alas it fails...

On Error GoTo Secondary_List:
    hospital = Application.WorksheetFunction.VLookup(iopcert, ocd1.Range("A1:C187"), 2, False)
    
Secondary_List:
        Set hosp_form = NoOpcert
        With hosp_form
            .Show
            miss_hosp = .hosp_list.Value
        End With
        Unload hosp_form
        Set hosp_form = Nothing
        If lngindex = -1 Then
            MsgBox "Nothing was selected!"
        Else
        End If

On error goto worked....