codeigniter中的paypal付款方式

I had posted following data to my paypal function in codeigniter controller

**Array
(
    [firstname] => firstname
    [email_id] => root@abc.com
    [address] => abc phase
    [select_country] => 1
    [select_state] => 1
    [select_city] => 1
    [zipcode] => 233234
    [address_same] => 0
    [shipping_address] => 
    [select_country3] => Select
    [shipping_state] =>abc 
    [shipping_city] => abc
    [zipcode3] => 123456
    [user_id] => 41
    [shipping_charge] => 50
    [grand_total] => 13569
    [quantity] => 1
    [payment_mode] => 1
    [submit] => submit
)**

i need to redirect my grand total and required data to paypal official link

https://www.paypal.com/cgi-bin/webscr

what all i need to post ..?

please guide for further procedure

Need to HTML form like this :

Example your array is $myArray

<?php
    $rand=rand();
?>
<form id="paypal_<?php echo $rand;?>" action="https://www.paypal.com/cgi-bin/webscr" method="post">
  <input type="hidden" name="cmd" value="_cart">
  <input type="hidden" name="business" value="<?php echo $myArray['email_id']; ?>">
  <input type="hidden" name="item_name" value="hat">
  <input type="hidden" name="item_number" value="123">
  <input type="hidden" name="amount" value="15.00">
  <input type="hidden" name="first_name" value="<?php echo $myArray['firstname']; ?>">
  <input type="hidden" name="last_name" value="Doe">
  <input type="hidden" name="address1" value="9 Elm Street">
  <input type="hidden" name="address2" value="Apt 5">
  <input type="hidden" name="city" value="Berwyn">
  <input type="hidden" name="state" value="PA">
  <input type="hidden" name="zip" value="19312">
  <input type="hidden" name="email" value="jdoe@zyzzyu.com">
  <input type="hidden" name="notify_url" value="your_notify_url" />
  <input type="hidden" name="currency_code" value="EUR">
  <input type='hidden' name='return' value="your_return_url"/>
  <input type="image" name="submit"
    src="https://www.paypalobjects.com/en_US/i/btn/btn_buynow_LG.gif"
    alt="PayPal - The safer, easier way to pay online">
</form>

Script for auto submit

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.4/jquery.min.js"></script>
<script>
$(document).ready(function(){
    $("#paypal_<?php echo $rand;?>").submit();
});
</script>

For details https://developer.paypal.com/docs/classic/paypal-payments-standard/integration-guide/formbasics/