Issue in submitting code to SVN

while committing my code to SVN I am开发者_JS百科 getting following error

Please help me how to resolve this issue ??

Obviously, there were some changes on ProjectOne/Classes/AESEncryption.m since your last update from the server. Your working copy needs an update before you can commit to the repo.

Do an update, in case of conflicts solve them and then try to commit again.