I have a form in which the user can either upload a file containing a list of widgets or manually enter the widgets into a text field. If the user manually enters the widgets into the text field, I use AJAX to serialize the form elements, send the data to the server, and process the response. If the user manually uploads a file I use an iframe to simulate a file upload with AJAX.
The issue is that the button to submit the form must only submit the form if the user is uploading a file of widgets. Therefore the input button must be of type "submit". The form must not be submitted if the user is manually entering the widgets in a text field. Therefore the input button must be of type "button" (to prevent the form from submitting) because the processing takes place on the page with theform.
The solution I came up with is depending on whether the user uploads the file or manually enters data, I use (or would like to use) Prototype JS's writeAttribute method to change the type attribute from "submit" (for the file upload) to "button" (for the manual entry) on the button to submit the request.
Of course IE has seizures with the writeAttribute and setAttribute methods.
1. is there perhaps a better way to change the submission control of the form?
2. What method is cross-browser compatible to change the "type" attribute of an input tag and the "action" attribute of a form tag?