在Ajax中，我希望有2个以上的输入功能。 我怎样才能做到这一点？

In Ajax, I want to have 2 and more input function. How Can I do this? That is, usually "q" is popular. But I want to add "p" parameter in ajax program. Below is my html-script code.

 <form>
 <input type="text" name="FirstName" maxlength="20" onkeyup="showUser(this.value)">
 <input type="text" name="LastName" maxlength="20" onkeyup="showUser(this.value)">
 </form>

 <br>
 <div id="txtHint"><b>Person info will be listed here.</b></div>

  <script>
  function showUser(str){

   if (str.length==0)
  { 
  document.getElementById("txtHint1").innerHTML="";
  return;
   }
   var xmlhttp=new XMLHttpRequest();
  xmlhttp.onreadystatechange=function()
 {
 if (xmlhttp.readyState==4 && xmlhttp.status==200)
  {
  document.getElementById("txtHint1").innerHTML=xmlhttp.responseText;
  }
 }

 var selectedLang = document.getElementById('lang').value;

 xmlhttp.open("GET","ds_hint_"+selectedLang+".php?q="+str,true);
 xmlhttp.open("GET","ds_hint_"+selectedLang+".php?p="+str,true);

 xmlhttp.send();
 } 
 </script>

In script, "xmlhttp.open("GET","ds_hint_"+selectedLang+".php?p="+str,true);" is added to re-search the first search result by "q" parameter.

So, my php code is below.

  mysqli_select_db($con,"ajax_demo");
  $sql="SELECT * FROM persons WHERE FirstName = '".$q."' and LastName = '".$p."'";

  $result = mysqli_query($con,$sql);

  echo "<table border='1'>
  <tr>
  <th>Firstname</th>
  <th>Lastname</th>
  <th>Age</th>
  <th>Hometown</th>
  <th>Job</th>
  </tr>";

  while($row = mysqli_fetch_array($result))
  {
  echo "<tr>";
  echo "<td>" . $row['FirstName'] . "</td>";
  echo "<td>" . $row['LastName'] . "</td>";
  echo "<td>" . $row['Age'] . "</td>";
  echo "<td>" . $row['Hometown'] . "</td>";
  echo "<td>" . $row['Job'] . "</td>";
  echo "</tr>";
  }
  echo "</table>";

  mysqli_close($con);
 ?>

I think PHP code is normal, but, script code is not sufficient for re-search function. How can i solve my script code?? Please, help me.

your query string should be like

  xmlhttp.open("GET","ds_hint_"+selectedLang+".php?q="+qstr+"&p="+pstr,true);

and your php

$q=$_GET['q'];
$p=$_GET['p'];
mysqli_select_db($con,"ajax_demo");
$sql="SELECT * FROM persons WHERE FirstName = '".$q."' and LastName = '".$p."'";

though as pointed out this is not filtering for sql injection I personally prefer pdo prepared statemants