diff --git a/Classes/IJInventoryWindowController.h b/Classes/IJInventoryWindowController.h
index c177020..3dcbea4 100644
--- a/Classes/IJInventoryWindowController.h
+++ b/Classes/IJInventoryWindowController.h
@@ -14,7 +14,7 @@
 @class MAAttachedWindow;
 @class IJItemPropertiesViewController;
 
-@interface IJInventoryWindowController : NSWindowController <NSCollectionViewDelegate, IJInventoryViewDelegate> {
+@interface IJInventoryWindowController : NSWindowController <NSWindowDelegate, IJInventoryViewDelegate> {
 	IJMinecraftLevel *level;
 	NSArray *inventory;
 	
@@ -43,6 +43,8 @@
 	// Document
 	BOOL dirty;
 	int64_t sessionLockValue;
+	int loadedWorldIndex;
+	int attemptedLoadWorldIndex;
 }
 
 @property (nonatomic, assign) IBOutlet NSSegmentedControl *worldSelectionControl;
diff --git a/Classes/IJInventoryWindowController.m b/Classes/IJInventoryWindowController.m
index 32c562f..2714eec 100644
--- a/Classes/IJInventoryWindowController.m
+++ b/Classes/IJInventoryWindowController.m
@@ -14,6 +14,8 @@
 #import "MAAttachedWindow.h"
 
 @interface IJInventoryWindowController ()
+- (void)saveWorld;
+- (void)loadWorldAtIndex:(int)worldIndex;
 @end
 
 @implementation IJInventoryWindowController
@@ -60,12 +62,42 @@
 #pragma mark -
 #pragma mark World Selection
 
+- (void)dirtyLoadSheetDidEnd:(NSWindow *)sheet returnCode:(int)returnCode contextInfo:(void  *)contextInfo
+{
+	if (returnCode == NSAlertOtherReturn) // Cancel
+	{
+		[worldSelectionControl setSelectedSegment:loadedWorldIndex-1];
+		return;
+	}
+	
+	if (returnCode == NSAlertDefaultReturn) // Save
+	{
+		[self saveWorld];
+		[self loadWorldAtIndex:attemptedLoadWorldIndex];
+	}
+	else if (returnCode == NSAlertAlternateReturn) // Don't save
+	{
+		dirty = NO; // Slightly hacky -- prevent the alert from being put up again.
+		[self loadWorldAtIndex:attemptedLoadWorldIndex];
+	}
+}
+
 - (void)loadWorldAtIndex:(int)worldIndex
 {
+	if (dirty)
+	{
+		attemptedLoadWorldIndex = worldIndex;
+		NSBeginInformationalAlertSheet(@"Do you want to save the changes you made in this world?", @"Save", @"Don't Save", @"Cancel", self.window, self, @selector(dirtyLoadSheetDidEnd:returnCode:contextInfo:), nil, nil, @"Your changes will be lost if you do not save them.");
+		return;
+	}
+	
 	[armorInventory removeAllObjects];
 	[quickInventory removeAllObjects];
 	[normalInventory removeAllObjects];
 	
+	[inventoryView setItems:normalInventory];
+	[quickView setItems:quickInventory];
+	[armorView setItems:armorInventory];
 	
 	[self willChangeValueForKey:@"worldTime"];
 	[level release];
@@ -74,10 +106,6 @@
 	inventory = nil;
 	[self didChangeValueForKey:@"worldTime"];
 	
-	[inventoryView setItems:normalInventory];
-	[quickView setItems:quickInventory];
-	[armorView setItems:armorInventory];
-	
 	statusTextField.stringValue = @"No world loaded.";
 	
 	if (![IJMinecraftLevel worldExistsAtIndex:worldIndex])
@@ -150,10 +178,12 @@
 	
 	dirty = NO;
 	statusTextField.stringValue = @"";
+	loadedWorldIndex = worldIndex;
 }
 
-- (void)saveToWorldAtIndex:(int)worldIndex
+- (void)saveWorld
 {
+	int worldIndex = loadedWorldIndex;
 	if (inventory == nil)
 		return; // no world loaded, nothing to save
 	
@@ -246,8 +276,7 @@
 
 - (void)saveDocument:(id)sender
 {
-	int worldIndex = [worldSelectionControl selectedSegment] + 1;
-	[self saveToWorldAtIndex:worldIndex];
+	[self saveWorld];
 }
 
 - (void)delete:(id)sender
@@ -478,6 +507,35 @@
 #pragma mark -
 #pragma mark NSWindowDelegate
 
+- (void)dirtyCloseSheetDidDismiss:(NSWindow *)sheet returnCode:(int)returnCode contextInfo:(void  *)contextInfo
+{
+	if (returnCode == NSAlertOtherReturn) // Cancel
+		return;
+	
+	if (returnCode == NSAlertDefaultReturn) // Save
+	{
+		[self saveWorld];
+		[self.window performClose:nil];
+	}
+	else if (returnCode == NSAlertAlternateReturn) // Don't save
+	{
+		dirty = NO; // Slightly hacky -- prevent the alert from being put up again.
+		[self.window performClose:nil];
+	}
+}
+
+
+- (BOOL)windowShouldClose:(id)sender
+{
+	if (dirty)
+	{
+		// Note: We use the didDismiss selector becuase the sheet needs to be closed in order for performClose: to work.
+		NSBeginInformationalAlertSheet(@"Do you want to save the changes you made in this world?", @"Save", @"Don't Save", @"Cancel", self.window, self, nil, @selector(dirtyCloseSheetDidDismiss:returnCode:contextInfo:), nil, @"Your changes will be lost if you do not save them.");
+		return NO;
+	}
+	return YES;
+}
+
 - (void)windowWillClose:(NSNotification *)notification
 {
 	[NSApp terminate:nil];
diff --git a/Classes/InsideJobAppDelegate.m b/Classes/InsideJobAppDelegate.m
index 481f44e..f123fd7 100644
--- a/Classes/InsideJobAppDelegate.m
+++ b/Classes/InsideJobAppDelegate.m
@@ -16,5 +16,13 @@
 - (void)applicationDidFinishLaunching:(NSNotification *)aNotification {
 	[inventoryWindowController worldSelectionChanged:nil];
 }
+- (NSApplicationTerminateReply)applicationShouldTerminate:(NSApplication *)sender
+{
+	BOOL shouldClose = [inventoryWindowController windowShouldClose:nil];
+	if (shouldClose)
+		return NSTerminateNow;
+	else
+		return NSTerminateCancel;
+}
 
 @end