This is a common fallback technique, but it has inherent limitations.
Also note that if there is no file input in the form then the request uses normal XHR to submit the form (not an iframe).The delay is used to allow the browser to render DOM updates prior to performing a native form submit.This improves usability when displaying notifications to the user, such as "Please Wait..." Default value: Identifies the iframe element to be used as the response target for file uploads.But the recommended solution is to test for the 'X-Requested-With' request header.If the value of that header is 'XMLHttp Request' then you know that the form was posted via ajax.Submitting a form with AJAX doesn't get any easier than this!
Returns the value(s) of the element(s) in the matched set in an array.
When using this option the plugin will make no attempt at handling the response from the server.
Default value: Callback function to be invoked after the form has been submitted.
This puts the burden on your server code to know when to use a textarea and when not to.
If you like, you can use the and then your server can always embed the response in a textarea.
If the 'before Submit' callback returns false then the form will not be submitted.