I have two JQuery UI autocomplete input fields. When an option is selected in the first one, the value of the selection will be used as condition for a database query that will send the source data for the second autocomplete field. My problem is how do I send the value of the first selection to the PHP page via Post method?

The code so far is shown below (this code is from a tutorial which used the GET method; but I want to use Post):

<script>

                          $("input#divisions").autocomplete ({
                                                      //this is the first input 
                          source : [
                                      { value: "81", label: "City1" },
                                      { value: "82", label: "City2" },
                                      { value: "83", label: "City3" }                                       ],
                          minLength : 0,
                          select: function(event, ui) {
                              $('#divisions').val(ui.item.label);

                              return false;
                          },
                          focus: function(event, ui){
                             $('#divisions').val(ui.item.label);
                             return false;    
                          },
                          change: function(event, ui){
                                                              //the tutorial has this value sent by variables in the URL; I want the selection value sent by POST. How can I change this?
                              c_t_v_choices = "c_t_v_choices.php?filter=" + ui.item.value;
                              $("#c_t_v").autocomplete("option", "source", c_t_v_choices);
                          }
                          }).focus (function (event)
                          {
                          $(this).autocomplete ("search", "");
                          });

                          $("#c_t_v").autocomplete({
                              source: "",
                              minLength: 2,
                              select: function(event,ui){
                                  //$('#city').val(ui.item.city);              
                              }
                          });   
</script>

Can anyone please help? Dont hesitate to let me know if you have any questions.