<?php
function jsdemo2_admin_settings() {
  $form['jsdemo2_author_max']=array(
    '#type' => 'textfield',
    '#title' => t('Maximum authors to display'),
    '#default_value' => variable_get('jsdemo2_author_max', 10),
    '#size' => 3,
    '#maxlength' => 3,
  );
  
  $form['jsdemo2_source_max']=array(
    '#type' => 'textfield',
    '#title' => t('Maximum sources to display'),
    '#default_value' => variable_get('jsdemo2_source_max', 16),
    '#size' => 3,
    '#maxlength' => 3,
  );

  $form['jsdemo2_subject_max']=array(
    '#type' => 'textfield',
    '#title' => t('Maximum subjects to display'),
    '#default_value' => variable_get('jsdemo2_subject_max', 10),
    '#size' => 3,
    '#maxlength' => 3,
  );

  return system_settings_form($form);
}

function jsdemo2_admin_settings_validate($form, $form_state) {
  if (!is_numeric($form_state['values']['jsdemo2_source_max'])) {
    form_set_error('jsdemo2_source_max', t('Please enter a number.'));
  }
  if (!is_numeric($form_state['values']['jsdemo2_author_max'])) {
    form_set_error('jsdemo2_author_max', t('Please enter a number.'));
  }
  if (!is_numeric($form_state['values']['jsdemo2_subject_max'])) {
    form_set_error('jsdemo2_subject_max', t('Please enter a number.'));
  }
}