Hello Jason,
I have one problem. I have one client who wants to connect quickbooks pro 2012 using asp.net 1.1. I have downloadedquickbooks pro 2012, quickbooks sdk 11 and I have successfully created and added web service to quickbooks web connector. Now what I have to do? I have read the response which you have given to Ravi but I am not getting how to use in asp.net 1.1. I am totally confused since last few days. I have tried all solutions available on internet and I am getting "Could not start quickbooks" error. Let me tell you that I am using visual studio 2003, windows xp, sql server 2005.

Here is my code in which I am getting this error:

Dim sessionBegun As Boolean = False
            Dim connectionOpen As Boolean = False
            Dim sessionManager As QBSessionManager
            'Create the session Manager object
            sessionManager = New QBSessionManager

            'Create the message set request object to hold our request
            Dim requestMsgSet As IMsgSetRequest = sessionManager.CreateMsgSetRequest("US", 1, 0.0)
            requestMsgSet.Attributes.OnError = ENRqOnError.roeContinue

            'Connect to QuickBooks and begin a session
            sessionManager.OpenConnection("", "Sample")
            connectionOpen = True
            sessionManager.BeginSession("", ENOpenMode.omSingleUser)
            sessionBegun = True

            Dim customerQueryRq As ICustomerQuery = requestMsgSet.AppendCustomerQueryRq()

            'Send the request and get the response from QuickBooks
            Dim responseMsgSet As IMsgSetResponse = sessionManager.DoRequests(requestMsgSet)
            Dim response As IResponse = responseMsgSet.ResponseList.GetAt(0)
            Dim customerRetList As ICustomerRetList = DirectCast(response.Detail, ICustomerRetList)

            Dim customers() As Customer

            If Not IsNothing(customerRetList) Then

                For i As Integer = 0 To customerRetList.Count - 1
                    Dim customerRet As ICustomerRet = customerRetList.GetAt(i)

                    Dim customer = New Customer
                    customer.Name = customerRet.Name.GetValue()
                    customer.QuickBooksID = customerRet.ListID.GetValue()
                    customer.EditSequence = customerRet.EditSequence.GetValue()
                    customers(i) = customer
                Next
            End If

I have to get all customer entries and display on aspx page.

Please help me in this or else provide me some sample code and steps which I have to take to connect quickbooks. Please help me I am totally lost.

Thanks