Modifying Existing Code to Check if the entry exists

Hi There,

I need your help,

I have a code below that works well with a userform that adds my data from my userform to an excel worksheet. It works great and all, but id like to modify it to have it check and see if the file number (fn) exists before writting it back to the worksheet, if it exists, then msgbox "Error: Record Cannot be added - (Duplicate Entry)" and do nothing else, if the file number does not exist, proceed as normal and execute the rest of the code.

With Me 
    Select Case .h9.Value 
    Case "ACTIVE" 
        Set ws = Worksheets("Active_Data") 
        iRow = ws.Cells(ws.Rows.Count, 1).End(xlUp).Offset(1, 0).Row 
         
        ws.Cells(iRow, 1) = .h1 
        ws.Cells(iRow, 2).Value = .h2 
         
        ws.Cells(iRow, 3).Value = fn 
        Me.h3.Text = fn 
         
        ws.Cells(iRow, 4).Value = .h4 
        ws.Cells(iRow, 5).Value = .h5 
        ws.Cells(iRow, 6).Value = .h6 
         
        If notify.Value = "True" Then 
            ws.Cells(iRow, 7).Value = "Yes" 
        Else 
            ws.Cells(iRow, 7).Value = "No" 
        End If 
         
        If remind.Value = "True" Then 
            ws.Cells(iRow, 8).Value = "Yes" 
        Else 
            ws.Cells(iRow, 8).Value = "No" 
        End If 
         
        ws.Cells(iRow, 9).Value = .h7 
        ws.Cells(iRow, 10).Value = .h8 
        ws.Cells(iRow, 11).Value = .h9 
        ws.Cells(iRow, 12).Value = .h10 
        ws.Cells(iRow, 13).Value = .h11 
        ws.Cells(iRow, 14).Value = .h12 
        ws.Cells(iRow, 15).Value = .h13 
         
        ws.Cells(iRow, 16).Value = Now 
        Me.h14.Value = Now 
         
        MsgBox "The record has been sucessfully added!" _ 
        , vbInformation + vbOKOnly, "Record added" 
         
    Case "INACTIVE" 
        Set ws = Worksheets("Inactive_Data") 
        iRow = ws.Cells(ws.Rows.Count, 1).End(xlUp).Offset(1, 0).Row 
        ws.Cells(iRow, 1) = .h1 
        ws.Cells(iRow, 2).Value = .h2 
         
        ws.Cells(iRow, 3).Value = fn 
        Me.h3.Text = fn 
         
        ws.Cells(iRow, 4).Value = .h4 
        ws.Cells(iRow, 5).Value = .h5 
        ws.Cells(iRow, 6).Value = .h6 
         
        If notify.Value = "True" Then 
            ws.Cells(iRow, 7).Value = "Yes" 
        Else 
            ws.Cells(iRow, 7).Value = "No" 
        End If 
         
        If remind.Value = "True" Then 
            ws.Cells(iRow, 8).Value = "Yes" 
        Else 
            ws.Cells(iRow, 8).Value = "No" 
        End If 
         
        ws.Cells(iRow, 9).Value = .h7 
        ws.Cells(iRow, 10).Value = .h8 
        ws.Cells(iRow, 11).Value = .h9 
        ws.Cells(iRow, 12).Value = .h10 
        ws.Cells(iRow, 13).Value = .h11 
        ws.Cells(iRow, 14).Value = .h12 
        ws.Cells(iRow, 15).Value = .h13 
         
        ws.Cells(iRow, 16).Value = Now 
        Me.h14.Value = Now 
         
        MsgBox "The record has been sucessfully added!" _ 
        , vbInformation + vbOKOnly, "Record added" 
         
    End Select 
End With

Any help with this is greatly appreciated.

Much thanks for all your help in advance.

Thanks,

Jay