我如何使用jQuery从选择框中获取一堆选定的ID

Question

I am trying to get selected ids from select drop-down using jquery. First drop down showing project name when user select project name then it moves to another select drop-down. and i want selected projects id also for mySql query. Please help how can i get bunch of ids and new drop-down create on selected base

Jquery code

     $(document).ready(function()
   {
     $("select").change(function()
       {
       var projectID=($(this).val());

  $.ajax({url:"addprojectname.php?projectID="+projectID,
    success:function(result){
   Addproject=result;
   //alert(Addproject);
  $('#selectedProject').html($('#selectedProject').html()+Addproject);
   }});});
 });

Html Code

     <?php 
       echo  '<div id="customProject" name="customProject"
     align="center"style="width:180px;overflow-y:auto;height:205px;
     border:2px solid;display:inline-block;" >';

   $query1 = mysql_query("SELECT * from projects");

 echo '<select id="projects_ID" size="12" multiple>';

  while($r1 = mysql_fetch_array($query1))
   {
  echo  '<option value='.$r1['project_id'].'>'. $r1['Project_name'] ."</option>";

  }
  echo "</select></div>";

 echo  '<div id="selectedProject" name="selectedProject"style="width:160px;
  overflow-  y:auto;height:205px;border:0.5px
  solid;margin-left:50px;; display:inline-block;" >';
 echo '</div>';?>

Answer 1

Try to maintain a array like

project_id => project_name

so that u don't need to store it separately