Suggest a Username

The purpose of this is to show you how you can create a "suggest a username" script. This script will suggest some new choices of usernames if the one the user enters is taken.

The source code for the random function we will be using:

Function GenPass()
   Dim fs
   Dim strTemp
   Set fs = CreateObject("Scripting.FileSystemObject")
     ' Get just the filename part of the temp name path
     strTemp = fs.GetBaseName(fs.GetTempName)
     'Hack off the 'rad'
     strTemp = Right(strTemp, Len(strTemp) - 3)
   Set fs = Nothing
End Function
How this function works
This function works by accessing the name of a randomly generated temporary file. Files normally would look like this radXC93D.tmp. The function simply hacks off the "rad" and the ".tmp" to retain the 5 random characters

Lets get down to business
Let assume for this project that I have an html page where new users select a username and password to register for my application. For simplicities sake I will skip all of the normal error checking I would do so we can focus on the core concepts of this article. The following code will be what we use to suggest usernames to the user if they are already taken.

First we'll take a look at the code and then you will see how it works
We'll assume we declared a connection to our database called "Conn"

For demonstration purposes only! Please be aware of SQL Injection, and techniques to avoid.

Dim UserName,Suggestions,X,N,MaxN,Temp ''Declare needed variables
Dim RS,sql

sql="SELECT * FROM Users WHERE UserName='" & UserName & "';"
Set RS=Conn.Execute(sql)

If RS.EOF then
    ''They picked a unique user name. It is safe for you to add them to the database


    Suggestions=4 ''Set this equal to the number of suggestions
    '''you wish to make
    X=0 ''the current number of suggestions made
    N=0 ''Loop iterations
    MaxN=1000 ''Maximum loop iterations

What has been done until this point:

  • Declared variables
  • If the UserName supplied by the user wasn't unique we initialized our variables
  • Set the current number of suggestions equal to zero because we haven't made any suggestions yet
  • We set the current loop iterations to zero and the maximum loop iterations to 1000. This is done just to prepare for the ultra-rare case where our algorithm never finds a unique UserName. We don't want to start an infinite loop! (the chances of this happening are slim to none, however)

Response.Write "<b>The UserName """ & UserName & """ is taken."
    Response.Write " May I suggest on of the following UserNames?</b><br>"

    Do Until X=Suggestions
        Temp=UserName & Right(GenPass,2) ''only use 2 didgits of the random password
         '''for our new suggestion

        sql="SELECT * FROM Users WHERE UserName='" & Temp & "';"
        Set RS=Conn.Execute(sql)

   if RS.EOF then
                        ''If we didn't find the password in the database it is unique.
                        ''So suggest it!
                             Response.Write(Temp & "<br>")
    X=X+1 '''bump up the current suggestion count
   end if
   N=N+1 ''We just went through the loop so bump up our loop counter
   If N=MaxN then
                         ''Ooops looks like we couldn't find the the number of unique
                         ''usernames we specified at the beginning of this script
                         Response.Write("<br>Couldn't find " & Suggestions & " unique")
                         Response.Write(" UserNames! Breaking from loop.....<br><br>")
   end if

end if

In the database I used for the live example "nplst" is a user. The script output would look like this:

The UserName "nplst" is taken. May I suggest on of the following UserNames?

This script can be easily modified to create random passwords for your visitors. These passwords should be emailed to the person whom registered.

What are the advantages of doing this?

Quite simply it helps to cut down on bogus e-mail addresses in your database. If you allow people to enter their own passwords up front you will begin to see a lot of addresses like "" and "" If they want access to your protected area they will need to supply a valid address with which to recieve your generated password. The default length for passwords from GenPass is 5. If you wanted to create a 10 character password you would simply say

Pass=GenPass & GenPass

or an 8 character pass

Pass =Right(GenPass & GenPass,8)

username password function

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