How can i get the results of a JHTML select.genericlist in a Joomla Module

you can install a plugin like sourcerer

after the install you'll have to enable the superadministrator to insert php or html code in joomla content, modules, etc. This is by default disabled also for super admins.

How to enable php, html insertion in joomla content is described here

Thanks a lot for your post. Yet the whole project - a few php programs with embedded html-code and JavaScripts - is called via wrapper. Because of the weak connection to the Joomla Session and User-DB i decided to put the whole bunch of code into an own module. But i don't know how to use the JHTML::selectionlist..... Need a simple example, like below but with the necessary HTML Part:
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## A default value -- this will be the selected item in the dropdown ##
  $default = 2;
 
  ## An array of $key=>$value pairs ##
  $months = array(1 => 'Jan', 2 => 'Feb', 3 => 'Mar', 4 => 'Apr');
 
  ## Initialize array to store dropdown options ##
  $options = array();
 
  foreach($months as $key=>$value) :
    ## Create $value ##
    $options[] = JHTML::_('select.option', $key, $value);
  endforeach;
 
  ## Create <select name="month" class="inputbox"></select> ##
  $dropdown = JHTML::_('select.genericlist', $options, 'month', 'class="inputbox"', 'value', 'text', $default);
 
  ## Output created <select> list ##
  echo '</br>'.$dropdown;
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How can i get the result of the selected value - (similar to the $_GET and $_POST?

Thanks a lot.