How to pass Parameter NetSuite RESTLet using Advanced REST client

How to pass Parameter NetSuite RESTLet using Advanced REST client. I Cant get parameter value.

function getRecord(datain)
{
    nlapiLogExecution('DEBUG','recordtype='+datain.recordtype);
    nlapiLogExecution('DEBUG','id='+datain.id);
    var sugu = nlapiLoadRecord(datain.recordtype, datain.id);

    return JSON.stringify(sugu);
}