pls help me, i am novice in asp

<%
Option Explicit
Dim strError, strSQL

'see if the form has been submitted
'If Request.Form("action")="register" 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
response.Write(strError)
'end if

'check if a password has been entered
elseif Request.Form("password") = "" Then
strError = strError & " Please enter a password<br>" & vbNewLine
response.Write(strError)

'check if the passwords are the same... but don't display it if the password field is blank.
elseif Request.Form("password") <> Request.Form("password_confirm")_
And Request.Form("password") <> "" Then
strError = strError & "- Your passwords do not match<br>" & vbNewLine
response.Write(strError)
end if
'// check if an error has occured

If strError = "" Then
'continue
'include database connection code
%>
<!--#include file="sqlconnection.asp"-->
<%

' On Error Resume Next


'// check for an error
'// ATTENTION: this should be changed depending on the database provider
'
If Err.Number = -2147217900 Then
strError = "- That username is already in use. Please choose another<br>" & vbNewLine
response.Write(strError)
Else If Err.Number <> 0 Then
strError = "- An error occured. " & Err.Number & " : " & _
Err.Description & "<br>" & vbNewLine


'record created... redirect
'// create the SQL
Else Response.Write "Your user name and password has been accepted."
strSQL = "INSERT INTO members ([username],[password]) VALUES " & _
"('" & Request.Form("username") & "','" & _
Request.Form("password") & "')"
'// run the SQL
objConn.Execute strSQL

Response.Redirect "login.asp?msg=" & Server.URLEncode("Thank you for registering")
Response.End
End If

'restore standard error handling
On Error Goto 0

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
End If
'End If

'Function fixQuotes(strData)
' fixQuotes = Replace(strData,"'","''")
'End Function
%>


here is my code for registration form... help me about how to check izzit the username exist in database
or not...
pls give me the code that can solve my problem... thanks alot

thank you , i can do it already from ur help...

great! Glad I could help