Try java script
First :
- Make a form whith plugin, and add hidden field
For exemple after display the form on your blog you see :
<input type="hidden" value="" id="12_element25" name="name" />
<input type="hidden" value="" id="13_element25" name="mail" />
<input type="hidden" value="" id="14_element25" name="password" />
the id off this field is : 12_element25 and 13_element25 and 14_element25
- and, display your form whith php everywhere you whant in your theme : page.php or single.php etc …
<?php echo Form_maker_fornt_end_main('[Form id="25"]'); // Display form
?>
- And juste after put this :
<script type="text/javascript">
var formUrl = "<?php $_POST['name']; ?>";
var formUr2 = "<?php $_POST['mail']; ?>";
var formUr3 = "<?php $_POST['password']; ?>";
document.getElementById('12_element25').value=formUrl;
document.getElementById('13_element25').value=formUr2;
document.getElementById('14_element25').value=formUr3;
element.setAttribute("value", "sample value");
</script>
- Open Chrome Developer Tools and see result (work for me)