regex not detecting space in username textbox

[mczxikb]

I have a asp:textbox taking a Username that is part of a Signup form for a new user account.Obviously I don't want the user to sign up using a space as a name so I have this regular expression which should keep the valid entry to ASCII characters between 3 and 16 in length with NO SPACES.but the no spaces doesn't work in practice. it works in Regex editors and checkers but not my aspx page. Any suggestions? ^([a-zA-Z0-9!@#$%^&*()-_=+;:'"|~`<>?/{}]{3,16})$|\smany thanks