Farida , You can implement it using the Value First SMS API like the following code:
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="SMS.aspx.cs" Inherits="SMS.SMS" ValidateRequest="false"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html>
<head>
<title>SMS Pace Client API Version 1.2</title>
</head>
<body>
<form action="http://api.myvaluefirst.com/psms/servlet/psms.Eservice2" method="post" runat="server">
<textarea name="data" cols="60" rows="16">
<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE MESSAGE SYSTEM "http://127.0.0.1:80/psms/dtd/messagev12.dtd">
<MESSAGE VER="1.2">
<USER USERNAME="" PASSWORD=""/>
<SMS UDH="0" CODING="1" TEXT="" PROPERTY="0" ID="1">
<ADDRESS FROM="ASPNetApp" TO="919831012345" SEQ="1" TAG="some clientside random data"/>
</SMS>
</MESSAGE>
</textarea>
<INPUT TYPE="SUBMIT" name="action" value="send"/>
</form>
</body>
</html>