Reverse Calculation

We Removed Incl Rate in Tally Prime 4.0 and add extra field Reverse Calculation Its Working 2.1 But Not working in prime 4.0 Please Help me

Code:

[#Form: Sales Color]
    Add:Bottom Button:RSCAL_Sales_ICFGInclTax

[Button:RSCAL_Sales_ICFGInclTax]
    Key : Ctrl+F12
    Action : Set : RSCAL_Sales_ICFGInclTax : Not ##RSCAL_Sales_ICFGInclTax
    Title : IF ##RSCAL_Sales_ICFGInclTax then "Normal Calculation" else "Reverse Calculation"
   
[Variable : RSCAL_Sales_ICFGInclTax]
    Type : Logical
    Default : No
    Persistent : Yes

[System : Variables]
    RSCAL_Sales_ICFGInclTax : No   
   
[#Line: EI ColumnOne]
    Option    : MYRSCAL EI ColumnOne
       
[!Line    : MYRSCAL EI ColumnOne]
    Add : Right Fields : Before:VCH RateTitle    : VCHRCalculationTitle,
   
[Field:VCHRCalculationTitle]
    Use: Name Field
    Info: "Reverse"
    Width: 12
    Align:Center
    Border    : Thin Left
    Style:Small Bold
    Color        : Blue
    Invisible    : @@RSCAL_InclTaxcfg
   
[#Line: EI ColumnOneRate]
    Option    : MYRSCAL EI ColumnOneRate
       
[!Line    : MYRSCAL EI ColumnOneRate]
    Add : Right Fields : Before:VCH RateTitle :VCHRCalculationTitle2
   
[Field:VCHRCalculationTitle2]
    Use: Name Field
    Info: "Calculation Rate"
    Width: 12
    Align:Center
    Border    : Thin Left
    Style:Small Bold
    Color        : Blue
    Invisible    : @@RSCAL_InclTaxcfg
   
[#Line: EI InvInfo]
    Option : MYRSCAL EI InvInfo

[#Line: CI InvInfo]
    Option : MYRSCAL EI InvInfo
   
[!Line: MYRSCAL EI InvInfo]
    Add : Right Fields : Before:VCH Rate :VCHRCalculation
   
[Field    : VCHRCalculation]           
    Use            : Rate Price Field
    Set Always    : Yes
    Width        : 12
    Storage        : ReverseCalculation
    Border        : Thin Right
    Format        : "NoZero,Decimals:2"
    Invisible    : @@RSCAL_InclTaxcfg
    Inactive    : $$IsEnd:$StockItemName
   
[#Field: VCH Value]
    Option : MYRSCAL VCH Value : @@RSCAL_Sales_ICFGInclTax
   
[!Field: MYRSCAL VCH Value]
    ResetVal    : If $$InCreateMode Or $$InAlterMode then (( $ReverseCalculation * $BilledQty )) / ( 100+ @@IsTaxAmt ) * 100 Else $$Value
   
[System:UDF]
    ReverseCalculation:Rate:1005
   
[System:Formula]
    RSCAL_Sales_ICFGInclTax    : ##RSCAL_Sales_ICFGInclTax AND @@SalesInvoiceMode
    RSCAL_InclTaxcfg            : NOT (@@RSCAL_Sales_ICFGInclTax AND (($$IsTCSOn AND @@IsIndian) OR @@IsExciseTraderOn OR @@IsIndianVAT OR @@IsKenyaVAT OR ($$IsServiceTaxOn AND (@@IsIndian OR @@IsMalaysia)) OR (@@IsGCCCountriesVATOn AND ##VARVchDate >= ##GVATApplicableDate AND $$IsInventoryOn) OR (@@IsGSTon AND $$IsInventoryOn)))
    IsTaxAmt: $GSTClsfnIGSTRateEx + $GSTClsfnCessRateEx