How to insert the node in binary tree

I want to create a binary search tree. If the data I add in it has already exists, then print "already exists". If the data I add in it doesn't exists, then print "successfully inserts". Try to insert 7 data "7,20,15,3,40,14,29". And then insert 15 and 25 to see the outcome. can someone help me please! Sincerely appreciate!