How can i apply a regular expression to the user name field for registration process.

Now in user name field if i put "           a      " (double quotes not included in the text) this text as user name it register me with the user. In Users table of dnn this text is saved as i enter it and in aspnet_Users table the API trim the spaces and enters only a in the table. I am not able to find this property in propertydefinitions table also.

Waiting for user good response.

The reason for applying regular expression is that i want to restrict the user for username choices. At the popular sites of mails when you register yourself no site except the spaces in the username. This can be an extra feature provided by the DNN but our team is considering it as a bug.