After you add a Button object to your form design, you can specify a format to submit data in the Submit tab of the Object palette. HTTP Submit buttons and Email Submit buttons are preconfigured to use specific submission formats. For more information about data submission formats, see
About submitting data using a button.
LiveCycle Designer ES supports four data submission formats:
URL-Encoded Data (HTTP Post) This format is the only data submission format for HTML forms.
See also 

Specifying the format for submitting data