assign php session variables on button submit w/o name -

what need store session variables on button event listener in php. code have below button , unchangeable have work it. need "email" , "username" form , store them session variables in php.

<div class="pmpro_submit">                  <span id="pmpro_submit_span">                    <input type="hidden" name="submit-checkout" value="1" />                    <input type="submit" class="pmpro_btn pmpro_btn-submit-checkout" value="submit , confirm &raquo;" />                 </span>   <span id="pmpro_processing_message" style="visibility: hidden;"> 

the input type="submit" button there's no way (so far) html code ever work php below. put name2 variable test if it's getting there won't. stumper

if (isset($_post['submit'])===true)   {  $_session['name2'] ="fred"; $_session['uersname'] = $_post['username']; } 

pass name submit button can check if (isset($_post['submit']).

example

  <input type="submit" name="submit" class="pmpro_btn pmpro_btn-submit-checkout" value="submit , confirm &raquo;" /> 

if cant add name submit button can check isset hidden field.

if(isset($_post['submit-checkout']))  {  $_session['name2'] ="fred"; $_session['uersname'] = $_post['username']; }