如何将表单数据提交到其他站点并获取数据？

I want to fetch data from government site, that has a login form and after user get logged in, the data are then displayed. I want to fetch those data into my site.

Here's what I am doing in index.html and process.php.

<form action="/post/process.php" method="post" id="form">
    <input type="hidden" id="cboOpt" name="cboOpt" value="1">
    <label for="txCno">Input Consumer No</label>
    <input type="text" value="" id="txCno" name="txCno"><br><br>
    <label for="cbSdiv">Select Division</label>
    <select id="cbSdiv" name="cbSdiv">
      <option value="0">Please Select</option>...<option value="7">Upper bazar</option>
    </select><br><br>
    <input type="hidden" value="Input K. No" name="txKno" id="txKno">
    <input type="hidden" value="Input Mobile No" name="txMno" id="txMno">
    <input type="hidden" value="Input Bill No" name="txBno" id="txBno">
    <input type="submit" value="Submit" name="submit">
</form>

<?php
if(isset($_POST['submit'])) {
    $cboOpt = $_POST['cboOpt'];
    $txCno  = $_POST['txCno'];
    $cbSdiv = $_POST['cbSdiv'];
    $txKno  = $_POST['txKno'];
    $txMno  = $_POST['txMno'];
    $txBno  = $_POST['txBno'];

    $postdata = http_build_query(
        array(
            'cboOpt' => $cboOpt,
            'txCno'  => $txCno,
            'cbSdiv' => $cbSdiv,
            'txKno'  => $txKno,
            'txMno'  => $txMno,
            'txBno'  => $txBno
        )
    );

    $opts = array(
        'http' => array(
            'method'  => 'POST',
            'header'  => 'Content-Type: application/x-www-form-urlencoded',
            'content' =>  $postdata
        )
    );

    $context  = stream_context_create($opts);

    $response = file_get_contents("http://secure.urjamitra.in/urjamitra/onlinepay/", false, $context);

    echo $response;
}
?>