Funcion Numero A Letra Visual Basic

Public Class NumeroALetra
Public Function Negritas(ByVal campo As String) As String
Dim formato As String
formato = "" & campo & ""
Return formato
End FunctionPublic Function variables_concepto(ByVal marca As String, ByVal modelo As String, ByVal año As String, ByVal color As String, ByVal nserie As String) As String
Dim convierte As NewNumeroALetra
Dim variables As String
Dim mr, md, a, cl, ns As String

If (marca "") Then
'mr = convierte.Negritas("Marca:")
mr = (" Marca:")mr = mr & " " & marca
Else
mr = ""
End If

If (modelo "") Then
'md = convierte.Negritas("Modelo:")
md = "Modelo:"
md= ", " & md & " " & modelo
Else
md = ""
End If

If (año "") Then
'a = convierte.Negritas("Año:")
a = "Año:"
a = "," & a & " " & año
Else
a = ""
End If

If (color "") Then
'cl = convierte.Negritas("Color:")
cl = "Color:"
cl = ", " &cl & " " & color
Else
cl = ""
End If

If (nserie "") Then
'ns = convierte.Negritas("No. de Serie:")
ns = "No. de Serie:"ns = ", " & ns & " " & nserie
Else
ns = ""
End If

variables = mr & md & a & cl & ns
Return variables
End Function
Public FunctionConvierte_Importe(ByVal importe As String, ByVal moneda As String) As String
Dim cantidad_letra As String
Dim u, d, c, um, dm, cm, ct As Integer
Dim cts As String
Dimnflot As Double

If (importe = "") Then
nflot = 0
Else
nflot = CDbl(importe)
End If

cm = CInt(Fix(nflot / 100000))
dm =...