Do you think there would be any harm in adding a unique constraint on the UserName column in the aspnet_Users table?  I don't think I have any use for the ApplicationId so I'd just prefer to have user names be unique as opposed to having just the ApplicationId/UserName combination be unique?  Thoughts?

Also, what would the syntax be for adding this unique constraint in SQL server? 

cant you simply use the createuserwizard control, it checks to see if the username allready exists?

you dont need a constraint...if you use the control

Hi,

Try this

Two methods to check UserName and Email availability

 //-- method to check Email availability
    public bool CheckEmail()
    {
        bool emailExsit = false;
        MembershipUserCollection users = Membership.FindUsersByEmail(Email.Text);
        foreach (MembershipUser user in users)
        {
            if (Email.Text == user.Email)
            {
                emailExsit = true;
                break;
            }
            else
            {
                emailExsit = false;
            }
        }
        return emailExsit;

    }

    //-- method to check user name availability
    public bool CheckUserName()
    {
        bool userExsits = false;
        MembershipUserCollection users = Membership.FindUsersByName(UserName.Text);
        foreach (MembershipUser user in users)
        {
            if (UserName.Text == user.UserName)
            {
                userExsits = true;
                break;
            }
            else
            {
                userExsits = false;
            }
        }
        return userExsits;
    }