You must have a SMS user account and sufficient credits with a SMS service provider. The provider will provide you techical specification with transmission parameters that you need to put into your application.

Use Kannel(Linux) or NowSMS(BillOS). You'll find it a very easy task. If
you don't wanna buy GSM modem, I suggest Billionton's USB modem (about
200K tomans) and if you wanna buy an AT enabled phone, I suggest Siemens
SL 45. You can buy a second handed one for 40-50K tomans.

If you have high traffic, I suggest you connect with one of 3 companies in
Iran whom have access to TCI's SMPP link like MAGFA or ADT.

I have some doubts..
1) Do I need to get SMS server ??
2) where can I get csend.exe?
3) lgeiran ??

1)I know for sending sms  through Internet it would be
pass through smsc(sms center), but I don't know how.
another ways are using gsm modems(see
http://pablo.za.net/gsm.html ) or serial port
connected to cell phone and javacomm-api.
2)I couldn't understand what you're meaning about
csend.exe
3)I've attached a manual doc for lgeiran. if you could
connect your app to YMessenger (I mean sending message
to someone in YMessenger list) it could be a fine
solution for you,Although your app would be depended
on LG HomNet portal.

i have a similar project(Send sms  From Web
appplication)....
in this applications u should create a sms packet and
send it to sms server...
your packet is customiz by sms server so sms pcket
strutcture changed by one sms server to others...
you should ask from how's that impelements your
GSM&Smpp Protocols....
otherwise! in your program you should only create a
CUSTOMIZED packet structure and write it to the
Spesifeid Address(Socket Address:IP,Port Number)

If you are looking for a framework to send  SMS from a
web page  and Yahoo! messenger and also receive SMS and
manage received SMSs, you can contact some companies
that have tools for these stuffs, I recommend you to
contact "Sourena Software Group" company and ask them
for more detail (call: +982144333879).

I am plesed to see ur mail...
I have GSM/GPRS 900/1800/ MHz modem (WAVECOM).....
I am working for a company so we can implement GSM & SMPP Protocal ourself...If cant then we will get from other compmay...Ok...My problem is in stage ONE.. How to write a program to create SMS packet from web  page.. pls advise me...

Take a look at www.cs-networks.net.

They provide a cool app that allows you to send messages all over the world.
The app is called Desktop SMS sender.

Regards,