OpenOffice BASIC IsNumber

I have to migrate document from MS Excel to Open Office with macros. Everything works fine except this function

 If Application.WorksheetFunction.IsNumber(Cells(12, 5)) = False Then
   MsgBox "Nesprávne zadané číslo účtu alebo kód banky!", vbCritical
   ActiveSheet.Protect Password:="****", DrawingObjects:=True, Contents:=True, Scenarios:=True
   Exit Sub
 End If

It's check for values inserted by user. But I get only this error:

BASIC runtime error Variabl开发者_JAVA百科e of object is not set

So I double checked my document, if cell E12 is not empty, but it was filled. Is there in Open Office a different way to check input format? Thanks

The number in Excel Visual basic is different like in oo. try use getCellByName("E12").Value this function returns you Number

If the line If Application.WorksheetFunction.IsNumber(Cells(12, 5)) = False Then fails saying object not set, and you've verified that Cells(12, 5) returns a a value, then the only possibilities that I can think of would be that either Application or Application.WorksheetFunction is Nothing.