Hello, @hoangphat9000 . It seems that you are having trouble logging in to one of your accounts here at Armor Games.
So that I could help you out, can I ask what account are you referring to? Are you having problems logging in to an alternate account that you use for MMOs, or are you having trouble logging in elsewhere?
What you will need to do is contact them (http://support.splitscreenstudios.com/) to ask for help migrating your Armor Games account over to your current SplitScreen account.
Note, you may need to create a new SplitScreen account before you can use their help submissions page: http://support.splitscreenstudios.com/index.php?/Core/Default/Index
Sorry that we do not have a way to help you out with this directly.