A frequent task for ASP developers is to create a members area style section of a website. This would normally involve registration, a login page, and then access to a section of the site that is only available to registered users. In this article James shows us how to do exactly that by using ASP and SQL Server. By the end of this article you'll have a fairly good idea of how you can implement your own members area on your site.
Creating a members area with ASP - The login.asp code (Page 4 of 6 )
Copy the code below into login.asp, and then we'll take a closer look:
<SPAN class=bodyCode><% Option Explicit Dim strError, strSQL, objRS ' see if the form has been submitted If Request.Form("action")="login" Then 'the form has been submitted ' // validate the form 'check if a username has been entered If Request.Form("username") = "" Then _ strError = strError & "- Please enter a username<br>" & vbNewLine 'check if a password has been entered If Request.Form("password") = "" Then _ strError = strError & "- Please enter a password<br>" & vbNewLine ' // check if an error has occured If strError = "" Then 'continue 'include database connection code %> <!--#include file="inc-dbconnection.asp"--> <% '// create the SQL strSQL = "SELECT id,password FROM members WHERE username='" & _ fixQuotes(Request.Form("username")) & "'" ' // run the SQL Set objRS = objConn.Execute (strSQL) ' // see if there are any records returned If objRS.EOF Then 'no username found strError = "- Invalid username or password<br>" & vbNewLine Else 'check password If objRS("password")=Request.Form("password") Then 'username/password valid 'save session data Session("loggedin") = True Session("userid") = objRS("id") ' redirect to members area Response.Redirect ("default.asp") Response.End Else 'invalid password strError = "- Invalid username or password<br>" & vbNewLine End If End If End If If strError <> "" Then 'output the error message 'add extra HTML... strError = "<p><font color=""#FF0000""> The following errors occured:" & _ "</font><br>" & vbNewLine & strError End If 'display message in URL.. (ie thank you for registering) If Request.QueryString("msg") <> "" And strError = "" Then strError = "<p>" & Request.QueryString("msg") & "</p>" End If End If Function fixQuotes(strData) fixQuotes = Replace(strData,"'","''") End Function 're-set session data (ie log out) Session("loggedin")="" Session("userid")="" %> <html> <head> <title>Members Area Login</title> </head> <body> <h1>Members Area Login</h1> <p>Please enter your username and password to access the Members Area.</p> <%=strError%> <form action="login.asp" method="POST"> <input type="hidden" name="action" value="login"> <table border="0"> <tr> <td><b>Username</b></td> <td><input type="text" maxlength=20 name="username" value="<%=Server.HTMLEncode(Request.Form("username"))%>"> </td> </tr> <tr> <td><b>Password</b></td> <td><input type="password" maxlength=20 name="password" value="<%=Server.HTMLEncode(Request.Form("password"))%>"> </td> </tr> <tr> <td> </td> <td><input type="submit" value="Login"></td> </tr> </table> </form> </body> </html>
A large proportion of this code is almost identical to that of register.asp. The code first checks to see if the form has been submitted.
If it has, it uses the same validation technique as before to see if a username and password has been specified. If it hasn't, an error message is displayed. If it has, then it checks the username/password combination by querying the database for that username.
If objRS.EOF Then the username hasn't been found; display error message. Otherwise, we check the password returned from the database, and compare it to the one the user has just entered. Once again, if they are incorrect, we tell the user that. If the username/password combination is correct, we set the loggedin value of our session data to 1, and also save the user id.
These session data variables are available outside login.asp, so our memberís pages can check if we are logged in or not. Therefore, once setting this data, we simply redirect to default.asp ; the members home page (we are assuming that you have a separate /members/ directory).