Steam maplestory start up wont let me change my username to login by.

[LepAdots]

For some reason the steam maplestory start up wont let me change my username to login with.. its really irratating me! if anyone can help me please comment.

[Jamillia]

http://steamcommunity.com/app/216150/discussions/0/864979455456086719/

[VGAHayden]

Email

Whenever i try to launch the game it comes up with a login screen but defaults to an email i dont use for the game. I can't seem to backspace it or anything and therfore can't login in with my only accaount.

Am i missing a way to change it?