prompt to save if closing form and changes have been made

SpriteLibrary/SpriteEntryForm.cs

@@ -371,7 +371,14 @@ namespace SpriteLibrary
 
         private void SpriteEntryForm_FormClosing(object sender, FormClosingEventArgs e)
         {
-            myDatabase.Save(); //try saving the file
+            if (PromptToApplyChangesAndContinue())
+            {
+                myDatabase.Save(); //try saving the file
+            }
+            else
+            {
+                e.Cancel = true;
+            }
         }
 
         private void pbImageField_MouseMove(object sender, MouseEventArgs e)