如何确定是否单击了选择选项并在提交表单之前对其执行某些操作

I just want to do something when an option is clicked on/set before submitting its containing form.

Here is my code

echo "  <form  method='post' action='employees.php?go'  id='searchform' >";
echo "<tr>","<td>","<select  name='inpuQuery'  style ='width:200px;border-radius: 25px;'>",
      "<option value='-1'>Filter:</option>",
      "<option value='Name'>Name</option>",
      "<option value='Surname'>Surname</option>",
      "<option value='ID_No'>ID_No</option>",
   "</select >",
 "<td>", "<tr>";

echo "<tr>","<td>"," <input style='border-radius: 25px;color:blue;width:200px;' type='submit'  name='filter' value='Search'> ","<td>", "</tr>";

//the if statement for if isset the search submit query
if(isset($_POST['filter'])){
    $criteria=$_POST['inpuQuery'];
    switch ( $criteria) {
    case "Name":
              echo "<input  type='text' style ='border-radius: 25px;width:200px;height:40px;'  placeholder ='enter first name to search by' name='name_query' > ";
               break;
    case "Surname":
               echo "<input   type='text'  style ='border-radius: 25px;width:200px;height:40px;'  placeholder='enter surname to search by' name='surname_query' > ";   
               break; 
    case "ID_No":
                echo "<input  type='text' style ='border-radius: 25px;width:200px;height:40px;'  placeholder ='enter ID Num to search by' name='id_query' > ";
            break; 
    } 
}