$(document).ready(function(){
  
  //region abhängig von land
	var land_id = new String;
	var region_id = new String;
	$("select#land_id").change(function(){
	 	region_id = $("#land_id").val();
		Abfrage = "&region_id=" + region_id;
		$.get("php/form_abfrage_region.php", Abfrage, function(x){
      $("#region_id").html(x);
    })
  })
 
})