diff --git a/lib/flight-booking-manager.js b/lib/flight-booking-manager.js
index dbaee68..5069b81 100644
--- a/lib/flight-booking-manager.js
+++ b/lib/flight-booking-manager.js
@@ -103,7 +103,7 @@ class FlightBookingManager extends Contract {
     async isSeatAvailable(ctx, txId, tm, seatNumber) {
         let seatOwner = await this._queryVariable(ctx, txId, 'seatOwner_' + seatNumber, null, tm);
 
-        return seatOwner === null;
+        return seatOwner === null || seatOwner === undefined || seatOwner.length === 0;
     }
 
     async queryNextAvailableSeat(ctx, txId, tm) {
@@ -282,10 +282,10 @@ class FlightBookingManager extends Contract {
     }
 
     async endFlight(ctx, txId, tm) {
-        let reservations = await this.queryBookedSeatsCount(ctx, txId, tm);
+        let seats = await this.querySeatsCount(ctx, txId, tm);
 
-        for (let i = 0; i < reservations; i++) {
-            if (!await (new ResourceManager()).setValue(ctx, txId, 'seatOwner_' + i, null, tm)) {
+        for (let i = 0; i < seats; i++) {
+            if (!await (new ResourceManager()).setValue(ctx, txId, 'seatOwner_' + i, '', tm)) {
                 throw new Error('Cannot change seat status. Data item is locked by another transaction!');
             }
         }
diff --git a/lib/resourceManager.js b/lib/resourceManager.js
index 4f87ef4..af0ab49 100644
--- a/lib/resourceManager.js
+++ b/lib/resourceManager.js
@@ -82,8 +82,11 @@ class ResourceManager extends Contract {
 
         if (tx) {
             const tm = tx.getTm();
+            const tmClientName = tm.split(',').filter(x => x[0] === 'C' && x[1] === 'N')[0].split('=')[1];
+            const currentClientName =  ctx.clientIdentity.getID().split('::')[1].split('/').filter(x => x[0] === 'C' && x[1] === 'N')[0].split('=')[1];
 
-            if (tm !== ctx.clientIdentity.getID()) {
+
+            if (tmClientName !== currentClientName) {
                 throw new Error('Message sender (' + ctx.clientIdentity.getID() + ') is not the designated transaction manager of global transaction!');
             }
         } else {