How to get the id of each form?

I want to get the id of each form, but displayed only the id of the first form.

add_shortcode( 'form','form_shortcode' );

global $form;


function form_shortcode($atts)
{
    global $form;

    $defaults = array(
        'id' => '0',
        'open_trigger' => '',
        'type' => 'button',
        'text' => 'open');
    extract( shortcode_atts( $defaults, $atts ) );

    wp_parse_args($atts, $defaults);

    $form = $atts;

    return get_form();
}

function get_megapoll_id()
{
    global $form;
    echo $form['id'];
}

How to get in the template file each id of the form?

plugin/form/template/default/template.php

<div id="<?php get_form_id(); ?>">

</div>

I want it to be so.

[form id="1"]
[form id="2"]

<div id="1">

</div>

<div id="2">

</div>

Sorry for my english.