Functionality  Prerequisites  Download/Installation  Usage  How it works  Known issues  Revisions 

Forget everything I published at this place before! Here goes a professional solution for sending SMS out of a VB program. I was tired of adapting my program to all those upcoming and declining web sites providing free SMS. Hence I defined a COM interface, which covers the needs of a typical application in terms of sending SMS. Your application runs against this interface and has no clue about the objects implementing the interface. I also provide a couple of COM objects implementing the interface. These COM objects are proxy objects invoking the actual interface of the SMS provider. They do not deliver the messages themselves. Currently there are proxy objects for Clickatell, SMSx, ICQ (free), kSMS (free) and SAP-internal usage. Clickatell and SMSx are not free but more reliable. Clickatell is pretty cheap so I prefer it. Please go to Clickatell thru this link. This makes me earn some cents.

The prerequisite for the main installation are:

• Windows Installer version 2.0.
  →Download for Windows 2000 and NT 4.0
  →Download for Windows 95, 98, ME
• VB6 runtime
  →Download
• Microsoft Windows Script
  →Download
• The VB project makes use of Eduardo's OLELIB.TLB. To avoid a version hell please download the typelib stuff directly from Eduardo's site. This is only required when you want to recompile the VB project. It is not required at runtime.
  →Download.

These components are not contained in the install package due to technical and licensing issues. The installer package will tell you whether one of these components is missing.

This third generation no longer uses XMLHTTP, ServerXMLHTTP, or AspTear. Instead it uses WinInet. This is good news and bad news. Good news because you no longer need buy or install one of these objects. And because coding a proxy becomes easier. You no longer need to care about cookies - mostly. Bad news as the technology is not server-capable because WinInet is not.

Please read these terms and conditions carefully before using this software. Use of this software indicates you accept these terms.

The msi installer can be downloaded from here. This version of the installation expects you to have VB runtime and related components installed. Please let me know when you need a more complete installation package because you want to install the software on a clean PC. After installation you have some more COM objects on your machine plus a sample application which you can invoke from the Start menu.

Start the program installed in the Start menu and send an SMS.

Please inspect the source code for detailed explanations. The best commented source projects are SendMessage.vbp and ProxyClickatell2.vbp. Please also notice the comments for the interface object "Klemid's interface for mobile messaging" in the Object Browser.

ICQ only allows 10 messages per day and is very slow
kSMS is very unreliable. It currently seems not to work at least for T-Mobile phones.

When you want to adopt this code to access other SMS providers you can give me an order to do that for some fee. When you want to waste your own time please consider the following hints:

• This is a developer's corner. From developer for developers. Therefore it expects you to be familiar with VB and a little bit with COM. I can't teach you VB.
• The easiest to use providers are those providing a Web service like SMSx or kSMS. This is because there is a standard way of accessing the interface and the interface is more or less guaranteed to be stable. Clickatell doesn't have an actual web service but an http-oriented interface. Clickatell also provides a COM object which does the http communication for you. This is used in the project ProxyClickatell1. Advantage of this project compared to ProxyClickatell2 is that you can use more sophisticated functions of the COM object that are not supported by my interface. Things become difficult when you start replaying standard web forms. The ICQ proxy is a sample for this.
• Concerning the latter: For simple sites inspect your service's HTML source and find out which URL it serves and what the parameters are. My tool Form Sniffer can help you to analyze the HTTP request issued by the form. A more sophisticated sniffer is HttpTracer. Please register this tool. It's worthwhile.
• Check whether the form fires an HTTP Post or Get. My code assumes HTTP Post. For HTTP Get it is slightly different but I have no sample for this.
• When your site requires a logon every time things become more complicated. You would have to fake the logon, maybe handle some redirects, and send the actual submit request. It may happen that you need to intercept a redirect in order to get some session information.
• Some sites use load balancing, i.e. the logon request is dispatched to the less busy server of a server family. For example, this is the case when the logon is submitted to http://www... and the next page's URL is http://www3... or something like this. This would force you to intercept the redirect and extract the redirection URL from the HTTP response.
• Once you implemented a proxy object, you need to add some registry information manually in order to give the Send program notice of it. This is because VB is not able to add component category information to a COM object. Even worse, each time you recompile the object, the previously entered registry information is lost. To accomplish this, take one of the Category.reg files as a template and replace the CLSID by the concrete class ID of your object. You can figure this out for example by using the Microsoft Visual Studio tool "OLE View".
• If you have a solution for other sites I would appreciate to get it for publishing.
• Some downloaders experienced compile problems: An error [BadImplements...] occurred. This can be circumvented by compiling only with project compatibility. It may have something to do with differing olelib.tlb versions.

01 Jul 2000	Initially submitted for site www.billiger-telefonieren.de
11 Jul 2001	www.billiger... has closed it's service due to misuse ;-)
04 Aug 2001	Submitted the next generation
04 Sep 2001	Added ASP support
04 Sep 2001	Added 'Send SMS' to this site
24 Oct 2002	Submitted the next generation using proxy objects
04 Dec 2002	Added missing source file modRegistry
03.Mar.2004	Links updated