hi~
im developing a system now for my thesis, and one of its features is,
in payroll module the system will automatically sends a msg to the users registered phone number that they can now claim their pay
the same with the payment module
the user/customer will authomatically receive a msg if they need to pay up for the services the company provides.

thank you~

You'll need to find an SMS Gateway provider. They will provide you with an API to send your messages.

Something like this would work

String urls, mno, sms;

urls= "www.smsjunction.com?m='";
mno=TextMobileno.Text.ToString();
sms=TextSms.Text.ToString();

urls=urls+mno+"',sms='"+sms;

Response.Redirect(urls);