onValidation.js

import("Product_lib");
import("system.translate");
import("system.result");
import("Date_lib");
import("system.vars");

var messages = "";

var startDate = vars.get("$field.VALID_FROM");
var endDate = vars.get("$field.VALID_TO");

if (!DateUtils.validateBeginnBeforeEnd(startDate, endDate))
    messages += DateUtils.getValidationFailString();

var priceList = {
                priceList: vars.get("$field.PRICELIST"),
                priceListId: vars.get("$field.PRODUCTPRICEID"),
                fromQuantity: vars.get("$field.FROMQUANTITY"),
                buySell: vars.get("$field.BUYSELL"),
                vat: vars.get("$field.VAT"),
                currency: vars.get("$field.CURRENCY"),
                validFrom: vars.get("$field.VALID_FROM"),
                validTo: vars.get("$field.VALID_TO")
            };
var identicalPriceList = ProductUtils.checkForIndenticalPriceLists(vars.get("$field.PRODUCT_ID"), priceList);
if(identicalPriceList != null)
{
    if (messages)
        messages += "\n";
    messages += translate.text("Identical price list found!");
}

if (messages)
    result.string(messages)