function makeTx() {
                var buyer_email = document.getElementsByName( "buyer-email" )[ 0 ].value;
                var goods_or_services = document.getElementsByName( "goods-or-services" )[ 0 ].value;
                var transaction_title = document.getElementsByName( "transaction-title" )[ 0 ].value;
                var transaction_details = document.getElementsByName( "transaction-details" )[ 0 ].value;
                var fee_payer = document.getElementsByName( "fee_payer" )[ 0 ].value;
                var amount = document.getElementsByName( "amount" )[ 0 ].value;
                var params = "buyer_email=" + buyer_email + 
                    "&session_id=" + localStorage.session_id +
                    "&goods_or_services=" + goods_or_services +
                    "&title=" + transaction_title +
                    "&description=" + transaction_details +
                    "&fee_payer=" + fee_payer +
                    "&amount=" + amount;
                var xhttp = new XMLHttpRequest();
                xhttp.onreadystatechange = function() {
                    if ( this.readyState == 4 && this.status == 200 ) {
                        var json = JSON.parse( this.responseText );
                        if ( json.status == "success" ) {
                            window.location.href = "/seller-payment.html?tx=" + json.id;
                        }
                    }
                }
                xhttp.open( "POST", "/settx/", true );
                xhttp.setRequestHeader( "Content-type", "application/x-www-form-urlencoded" );
                xhttp.send( params );
            }