Answer to Yamini Surender's Question

//########## CLIENTSCRIPT ##########
var SEARCHMODULE, RECORDMODULE;
define(['N/search', 'N/record'], runClientscript);

function runClientscript(search, record){
    SEARCHMODULE = search;
    RECORDMODULE = record;

    //*********** HELPER FUNCTIONS ***********
    function create_amort_schedule(recordid) {//Here you receive the record id. Alternatively you can use SS 1.0 nlapiGetRecordId() but its deprecated.
        var YOUR_RECORD_TYPE = 'custrecord_XXXX';
        var fieldLookUp = SEARCHMODULE.lookupFields({ type: YOUR_RECORD_TYPE, id: recordid, columns: ['custrecordpfg_adv_loan_pymt_type']});//Doing a lookup cause its faster than loading the record
        var v_loan_pymt_mthd = fieldLookUp.custrecordpfg_adv_loan_pymt_type;
        alert(v_loan_pymt_mthd);
        return;
    }

    var returnObj = {};
    returnObj.create_amort_schedule = create_amort_schedule;
    return returnObj;
}

//########## USEREVENT ##########
var WIDGETMODULE;
/**
 *@NApiVersion 2.x
 *@NModuleScope Public
 *@NScriptType UserEventScript
 */
define(['N/ui/serverWidget'], runUserEvent);

function runUserEvent(widget) {
    WIDGETMODULE = widget;

    var returnObj = {};
    returnObj.beforeLoad = beforeLoad;
    return returnObj;
}

function beforeLoad(context) {
    if (context.type == context.UserEventType.VIEW) {
      context.form.clientScriptFileId = 13553;
      context.form.addButton({
        id : 'custpage_some_button',
        label : 'Schedule',
        functionName : 'create_amort_schedule(' + context.newRecord.id + ')' //Notice how you need to pass the id of the record as an argument. Your clientscript will receive it.
      });
    }
    return;
}