Create a simple module

• Create a directory called "modules" in "site/all" .(all the modules should be put in "site/all/modules").
• Create a ".infor" file as the following format(must have the same name as ".module" file and should be reside in the same directory):
• Create a ".module" file
   ; $Id$ #comment
  name = Annotate #the displayed name of the module
  description = Allows users to annotate nodes. #If contains punctuation, quotes are required
  dependences[] = module_name #other modules that the module requires
  dependences[] = module_name
  ....
  package = Example
  version = VERSION
  core = 6.x #this must be exists,otherwise an error will occur-"This version is incompatible with the 6.1 version of Drupal core"
  
  
• Create a ".install" file if tables are needed by this module

         create two functions modulename_install ,modulename_uninstall:

      Visit "admin/build/modules" to enable the module 

function modulename_install() {
   drupal_set_message(t(........'));
   switch ($GLOBALS['db_type']) {
    case 'mysql': 
    case 'mysqli':
       db_query("CREATE TABLE table_name(
         // Your SQL
        )/*!40100 DEFAULT CHARACTER SET utf8 */;"
       );
      $success = TRUE;
      break;
   case 'pgsql':
      db_query("CREATE TABLE table_name (
       );"
       );
      $success = TRUE;
      break;
   default:
      drupal_set_message(t('Unsupported database.'));
  }
  if ($success) {
     drupal_set_message(t('.........'));
  } else {
     drupal_set_message(t('..........'),'error');
 }
}

function modulename_uninstall() {
   db_query("DROP TABLE {table_name}");
}

•