When using a subscribe or unsubscribe forms, it is possible to pass values entered in those forms to landing pages. This allows for the creation of features like progressive subscribe forms. This is accomplished by creating a form using the Subscription Form Wizard, defining a Landing Page, and then editng the HTML to add the hidden goto_pass_along input field(s) to the form.
The goto_pass_along field tells the listctrl program which fields to append to the landing (goto) page. The goto_pass_along_aliases code allows you to use your own names in case the form field names don't suit your application.
To define which fields append to your landing page URL, enter one or more field names as the value for the goto_pass_along form field. Separate multiple entries by commas or semicolons. The fields you pass along will be visible in the address bar of the subscriber's browser. To if you would like the field name shown in the address bar to be different than what it is in the platform, add a hidden goto_pass_along_aliases input to your form. If goto_pass_along_aliases is used, each value in the goto_pass_along input must have a corresponding value in goto_pass_along_aliases.
In the example below, the hidden goto fields appear in red. The goto_pass_along code identifies the fields email and custom_favorite_flavor to use. The optional goto_pass_along_aliases stipulates that when these fields are appended they use the names email and flavor.
<form action="http://whatcounts.com/bin/listctrl" method="post">
<input type=hidden name="slid" value="10888353310">
<input type=hidden name="cmd" value="subscribe">
<input type=hidden name="format" value="plain">
<input type=hidden name="goto" value="http://whatcounts.com/bin/hello">
<input type=hidden name="goto_pass_along" value="email,custom_favorite_flavor">
<input type=hidden name="goto_pass_along_aliases" value="email,flavor">
Email:<input type=text name=email size=12>
Favorite flavor: <input type=text name="custom_favorite_flavor" size=15>
<input type=submit value="Subscribe">
The GOTO url in this form is the dynamic landing page, the fields email and custom_favorite_flavor will be appended to the URL. If you had entered firstname.lastname@example.org and Strawberry as values into the form, upon submission you would be redirected to the URL: