populate a form programmatically in drupal

I need to populate the form fields programmatically in drupal. I understand that there are 2 approaches:

1. 开发者_运维技巧using drupal_execute($form_item,value,$form_state)

2. using form_set_value($form_id,$form_state)

Any working examples would be helpful

I tried the following code which gives the drupal white screen of death

function form_validate($form, &$form_state){
  $form_id ='myform';
  $form_state['values'] = array(
    'name' => 'Test',    
  );
  drupal_execute($form_id, $form_state);  // this statement leads to white screen of death
}

I assume you are trying to fill out a field in the form during validation, after the user submits it? I assume this because you are using a validate function.

If so, there is no need for the drupal_execute() function, as the form will be submitted after it passes validation no matter what. I think what you want might be more like this:

function form_validate($form, &$form_state) {
  $form_state['values']['name'] = 'test'; 
}

You should use:

<?php
$form_id = 'mymodule_form_id';
$rendered_form = drupal_get_form($form_id);
print $rendered_form;
?>

See:

http://api.drupal.org/api/drupal/includes--form.inc/function/drupal_get_form/6