Script To Automatically alert when the same item occurs in the PO Line

/**
 * @NApiVersion 2.x
 * @NScriptType ClientScript
 * @NModuleScope SameAccount
 */
/*******************************************************************
 *   ClientScript
 ****************************************************************
 *
 * Date: 11/01/2023
 *
 * Author: Jobin and Jismi IT Services LLP
 *
 * REVISION HISTORY
 *
 * Revision 1.0
 *
 * Description: Script to check whether the purchase order item lines contains duplicates
 *
 ***************************************************************/
define(['N/currentRecord', 'N/search', 'N/ui/dialog', 'N/ui/message','N/url'],
    /**
     * @param{currentRecord} currentRecord
     * @param{search} search
     * @param{dialog} dialog
     * @param{message} message
     *  @param{message} url
     */
    function(currentRecord, search, dialog, message,url) {
        /**
         * Function to check whether the elements in an array are same or not
         * @param itemArray
         * *@param arrLength
         */

        function compareItemLoc(itemArray, arrLength) {
            try {
                // initialize ifPresent as false
                var ifPresent = false;

                // ArrayList to store the output
                var al = new Array();

                for (var i = 0; i < arrLength - 1; i++) {
                    for (var j = i + 1; j < arrLength; j++) {
                        if (itemArray[i] == itemArray[j]) {
                            if (al.includes(itemArray[i])) {
                                break;
                            }
                            else {
                                al.push(itemArray[i]);
                                ifPresent = true;
                            }
                        }
                    }
                }

                if (ifPresent == true) {

                    return al;
                }

            }catch (e) {
            }
        }
        /**
         * Validation function to be executed when record is saved.
         *
         * @param {Object} scriptContext
         * @param {Record} scriptContext.currentRecord - Current form record
         * @returns {boolean} Return true if record is valid
         *
         * @since 2015.2
         */
        function saveRecord(scriptContext) {

            try {
                // get the current PO record

                var poRec=scriptContext.currentRecord;
                var poItemCount=poRec.getLineCount({sublistId:'item'})
                console.log("poItemCount",poItemCount)
                // Loop through the item line
                var i;
                var itemArray=[];
                var poItemId
                for (i=0;i<poItemCount;i++){
                    poItemId = poRec.getSublistValue({sublistId: 'item', fieldId: 'item', line: i})
                    itemArray.push(poItemId)
                }

                var arrLength=itemArray.length
                // function to check whether the array contains duplicates
                var duplicates=compareItemLoc(itemArray,arrLength)
                // create alert message
                if (duplicates){
                    var content2 = "Please remove duplicate Items in this purchase order!! " ;
                    var options = {
                        title: "Purchase order item line Suggestions",
                        message:  content2
                    };
                    dialog.alert(options);
                    return false
                }

            return true
            }catch (e) {
                console.log("error @ saveRecord",e)
            }
        }

        return {
            saveRecord: saveRecord
        };

    });