how to make previously entered values appear for multistep forms after validation errors

Question

so evidently if I turn a form into a multistep form:

  if(!isset($form_state['storage']['step']))
    $form_state['storage']['step'] = 1;

and do form_set_error() in validate

when the validation error appears, the values that I previously put in would disappear.....

so If I enter a value into a textbox in a multistep form then hit continue then validation error appears, the textbox will now be empty instead of being filled with my previously entered values as it would happen normally

is there a way to prevent this from happening without manually reentering the default values for every form element?

fyi I'm using drupal 6

Answer 1

I was bitten by a similar case in a multistep form scenario, though in my case it was use of the "Previous" button that didn't preserve user entered values.

Initially I was under the impression that D7's form_builder() would automatically merge user data in $form_state['values'] back into the '#value' property of the form elements on previous step's subform, but this never happened!

After reading carefully through examples module, form_example/form_example_wizard.inc, I realized that I had to use:

'#default_value' => !empty($form_state['values']['my_elem']) ? $form_state['values']['my_elem'] : '',

on all form elements that I wanted to "remember" their user input!