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