I am very new to asp programming. I have a page where i get data from a table and i can modify them. I open my connection

<% 

cId = Request.QueryString("Id") 

' creazione dell'oggetto di connessione ADODB 
Set dbconn = Server.CreateObject("ADODB.Connection") 

' indicazione della connessione odbc sul server 
dbconn.ConnectionString =Application("Aupd_connectionstring") 
dbconn.Open Application("dbconn_RuntimeUserName"),Application("DbConn_RuntimePassword") 

SQLQuery= "SELECT Usrs.Id, Usrs.psw, Usrs.Cli, Usrs.Mail, Usrs.Tipo, Usrs.Area, Usrs.Act " & _ 
"From Usrs " & _ 
"Where Id='" & cId & "' " & _ 
"order by Id" 

Set RS=dbconn.Execute(SQLQuery) 

then i write my data using html commands
At the end of my page i have a button and i create a btnsave_onclick function

<script LANGUAGE="vbscript"> 
Sub btnsave_onclick 

dbconn = CreateObject("ADODB.Connection") 
dbconn.ConnectionString =Application("Aupd_connectionstring") 
dbconn.Open Application("dbconn_RuntimeUserName"),Application("DbConn_RuntimePassword") 

SQLQuery= "Update Usrs Set Cli='" & Trim(CodApp.Value) & "', Psw='" & Trim(Password.Value) & "'," & _ 
"Mail='" & Trim(Mail.Value) & "' " & _ 
"Where Id='" & trim(Codice.Value) & "'" 
msgbox(SQLQuery) 
dbconn.Execute(SQLQuery) 
window.Close 
End Sub 
</script> 

The problems are that in this function some vb commands are not correct or are not executed and i can use Application variables from file global.asa. If i exclude all the commands and leave only the window.close command the function is executed so the problem is in the syntax i use.
Someone can help me ? i have to save data and i need to understand which kind of commands to use and how can access the variables stored in global.asa and the difference between source in sub function and that in <% at the top of my asp page when i open the table and run a query.

Thanks in advance......