Need to pass user input from 1 form to another on the same page - forms

Question

I am do not know .php at all but have a problem on one of my websites.
1. There are 2 forms for payment processing on a single page.
2. Each form has a separate submit button.
The problem.
I need to pass some of the user input from form one on to form two.
Note. this is on the same page.
Form 1
<input type="hidden" name="payfast_url" id="payfast_url" value="https://www."/>
<input type="hidden" name="merchant_id" id="merchant_id" value="xxxxx"/>
<input type="hidden" name="merchant_key" id="merchant_key" value="xxxxx"/>
<input type="hidden" name="return_url" id="return_url" value="payment_finished.html"/>
<input type="hidden" name="cancel_url" id="cancel_url" value="payment_cancelled.html"/>
<input type="hidden" name="notify_url" id="notify_url" value="/payment_notify.html"/>
<input type="hidden" name="item_name" id="item_name" value="Product name"/>
<input type="hidden" name="item_description" id="item_description"value="description"/>
<input type="hidden" name="email_confirmation" id="email_confirmation" value="1"/>
<input type="hidden" name="confirmation_address" id="confirmation_address" value=""/>
<input type="hidden" name="amount" id="amount" value="price" />
<input type="hidden" name="payment_id" id="payment_id" value="website_sales" />
<span class="formlable">Name</span><input name="name_first" id="name_first"type="text" value="" class="forminput"/>
<span class="formlable">Surname</span> <input name="name_last" id="name_last" type="text" value="" class="forminput"/>
<span class="formlable">E-Mail</span> <input type="text" name="email_address" id="email_address" value="" class="forminput"/>
<span class="formlable">Post Address</span> <input name="custom_str1" id="custom_str1" type="text" value="" class="forminput"/>
<span class="formlable">City</span><input name="custom_str2" id="custom_str2" type="text" value="" class="forminput"/>
<span class="formlable">Postal Code</span><input name="custom_str3" id="custom_str3" type="text" value="" class="forminput"/>
<input type="button" value="EFT Payment" onclick="quickPostPaymentToPayFast(document.getElementById('payfast_url').value);" id="button" method="post"/>
Form 2
<form name="CreditCards" action="https://www.mygate.co.za/.cfm" method="post"/>
<input type="hidden" name="Mode" id="Mode" value="0"/>
<input type="hidden" name="txtMerchantID" id="txtMerchant" value="xxxxxxx"/>
<input type="hidden" name="txtApplicationID" id="txtApplicationID" value="xxxxxxxx"/>
<input type="hidden" name="txtMerchantReference" id="txtMerchantReference" value="1234"/>
<input type="hidden" name="txtPrice" id="txtPrice" value="1234"/>
<input type="hidden" name="txtCurrencyCode" id="txtCurrencyCode" value="ZAR"/>
<input name="txtRedirectSuccessfulURL" value="success_failure.php" readonly="true" type="hidden"/>
<input name="txtRedirectFailedURL" value="success_failure.php" readonly="true" type="hidden"/ >
<input type="hidden" name="txtQty" id="txtQty" value="1"/>
<input type="hidden" name="txtItemDescr" id="txtItemDescr" value="descr"/>
<input type="hidden" name="txtItemAmount" id="txtItemAmount" value="449.00"/>
<input type="hidden" name="txtRecipient" value="<?php $_POST["name_first"]; ?>"/>
<input type="hidden" name="txtShippingAddress1" value="<?php $_POST["name_last"]; ?>"/>
<input type="hidden" name="txtShippingAddress2" value="<?php $_POST["email_address"]; ?>"/>
<input type="hidden" name="txtShippingAddress3" value="<?php $_POST["custom_str1"]; ?>"/>
<input type="hidden" name="txtShippingAddress4" value="<?php $_POST["custom_str2"]; ?>"/>
<input type="hidden" name="txtShippingAddress5" value="<?php $_POST["custom_str3"] ?>"/>
<input type="submit" id="button4" value="Credit card" />
</form>
name_first
name_last
email_address
custom_str1
custom_str2
Custom-str3
from the first form must be transfered into the second form as well
thanks

Answer 1

You should think of using some client-side JavaScript. I'd recommend using jQuery.
Not sure whether you have any experience in JS but that won't be very complex.
Basically, all you have to do is:
1) Read the value of the first input
email = $('#email_address').val()
2) Assign it to the other field (not sure what fields you want to assign)
$('#txtShippingAddress2').val(email)
Then just bind this code to your submit button or anywhere you need it.
You can find out more about jQuery at http://jquery.com/