How To Send Hidden Php Variable With Html Form

I just thinking how to set and send PHP variable with HTML form, from first.php to second.php. Actually my first code looks that:

/*SOME

Solution 1:

Just add a new input with type hidden within your <form> </form>

<?php$your_php_var=5;?></form><formaction='add.php'method='post'><inputtype="hidden"name="email"value="<?phpecho$your_php_var; ?>"><inputtype='text'name='account'><inputtype='submit'value='Add'></form>

See more here http://www.html-form-guide.com/php-form/php-form-variables.html