This program will demonstrate the BTree data structure.

When you run this program, you can choose to enter your data by:
   1.  Manually - You enter the data 1 by 1 (by select 1 from the menu)
   2.  Automatically - You can enter the file name which contains your data and
                       the program will read the file and insert the data
                       accordingly (by select 2 from the menu)

After the data is inserted, you can perform the following:
   1. Insert another data - Similar with insertion
   2. Search Data - This will return a nodes which contains the data you look
                    for (by select 3 from the menu)
   3. Print - You can print the tree is
      1)  In-Order Travelsal       (by select 4 from the menu)
      2)  Level Order Traversal    (by select 5 from the menu)

At the end, you can select 6 to quit this program