UserParameter Error

[NachoShaw]

Hey

Im getting thrown an error in my function. I have a User Parameter in my part called CONVERT_FT and its unit is set to ft. Here is my code

Friend Function QuantifyLengthAsFT(ByVal length As String) As String

            Dim ret As String = String.Empty

            Dim oParams As UserParameters = CType(_BMDef.Parameters.UserParameters, UserParameters)
            Dim ParameterUnits As UnitsTypeEnum = UnitsTypeEnum.kFootLengthUnits
            Try
                Dim P As UserParameter = oParams.Item("CONVERT_FT")

                P.Expression = length
                Dim r As Double = CType(oParams.Item("CONVERT_FT").Value, Double)
                ret = ConvertValueToFT(CType(r, Double)) & " " & P.Units
                P.Expression = "0 ft"
            Catch ex As Exception
                ret = "Not Value"
            End Try

            Return ret
        End Function

(Assume _BMDef is a ComponentDefinition)

As i step through the function, the error is thrown on this line

Dim P As UserParameter = oParams.Item("CONVERT_FT")

and the error is

{The parameter is incorrect. (Exception from HRESULT: 0x80070057 (E_INVALIDARG))"}

I have another similar function with the unit as inches and that doesnt have an error

Any ideas?

Thanks

[NachoShaw]

figured it out, i was using the wrong document...