Проблема с полем типа Date/time

         Dim vFromDate  As Variant
Dim vToDate  As Variant

получение значений полей
vFromDate = DocCurrent.GetItemValue( "FromDate" )(0)
vToDate = DocCurrent.GetItemValue( "ToDate" )(0)

Dim x As Variant, y As Variant, z As Variant
x = 100                        Numeric value
y = CDat(100)                     Numeric date value
z = "Nov 2, 1983"                 String representing a date
Print IsDate(x)                Output: False
Print IsDate(y)                Output: True
Print IsDate(z)                Output: True
Print IsDate("100")            Output: False
Print IsDate("Nov 2, 1983")    Output: True

Dim vFromDate       As Variant       Дата, с которой идет поиск
Dim vToDate         As Variant       Дата, по которую идет поиск

получение значений полей
vFromDate = DocCurrent.GetItemValue( "FromDate" )(0)
vToDate = DocCurrent.GetItemValue( "ToDate" )(0)

проверка, правильно ли введен формат даты поиска
If Not ( Isdate( vFromDate ) Or vFromDate= "" ) Or Not ( Isdate( vToDate ) Or vToDate = "" ) Then
stErrMsg = "Неправильный формат введенной даты"
Exit Function
End If

 if Len( vFromDate ) = 0 or Len( vToDate ) = 0 then Exit Function
if Not Isdate( vFromDate ) or Not Isdate( vToDate ) then Exit Function

vFromDate = DocCurrent.GetItemValue( "FromDate" )(0)

If IsEmpty(DocCurrent.GetItemValue( "FromDate" )) then MsgBox("Ошибка") else vFromDate = DocCurrent.GetItemValue( "FromDate" )(0)

If Isempty( doc.FromDate ) Then MsgBox "Ошибка"

If Isempty( doc.FromDate ) Then MsgBox "Ошибка"