On my Form, I have a Text Box, in which a user will
type any message. Whenever I type in or pasted some
test line by line on it, the Text Box successfully
accepted all the text without any limit. But if a
WORD document of a big length is pasted on it, or a
decrypted message of big length is transferred from my
application, it shows a length of 65535 characters, and
the rest of the message is lost.

What is the problem?