Browser Back Button click event javascript

I am using the below code but window.onBeforeUnload is not working with back button.. how can i apply the below code for the click event of back button?

  window.onBeforeUnload = function () {
            if (document.referrer.indexOf('Create') > 0 || document.referrer.indexOf('Edit') > 0) {

                if (document.referrer.indexOf('/BatchProcessing/GasBottleBatch') > 0)
                    document.location = '/BatchProcessing/GasBottleBatch/Edit/' + getParameterByName('P_BatchId');
                else if (document.referrer.indexOf('/BatchProcessing/BulkLpgBatch') > 0)
                    document.location = '/BatchProcessing/BulkLpgBatch/Edit/' + getParameterByName('P_BulkBatchId');
                else
                    history.back();
            } else {
                history.back();
            }
            return false;

        };