如何在if语句中使用输入字段的值

Question

I have two input fields. One is to search auto suggest product names using jquery.autocomplete, and in my database I have column name product left, and I want to display it in the second input, is that possible?

For example: I have a product called apple with product left of 30. apple will display in the first input field after typing, and at same time 30 must appear in the second field.

<form action="sales.php" method="post">
    <input name="productlist" type="text" id="productlist" size="20"/>
    <input name="productleft" type="text" value=""/>
</form>

call jquery ui

<script type="text/javascript" src="js/jquery.autocomplete.js"></script>
<script>
  $(document).ready(function(){
   $("#productlist").autocomplete("psuggest.php", {
        selectFirst: true
    });
  });
  </script>

inside psuggest.php

<?php
    $q=$_GET['q'];
    $my_data=mysql_real_escape_string($q);
    $mysqli=mysqli_connect('localhost','root','','saganatracker') or die("Database Error");
    $sql="SELECT pdesc FROM products WHERE pdesc LIKE '%$my_data%' ORDER BY pdesc";
    $result = mysqli_query($mysqli,$sql) or die(mysqli_error());

    if($result)
    {
        while($row=mysqli_fetch_array($result))
        {
            echo $row['pdesc']."
";
        }
    }
?>

Answer 1

Use parameter onselect from .autocomplete() to bring the number of item left :

$(document).ready(function(){
    $("#productlist").autocomplete("psuggest.php", {
        selectFirst : true,
        onselect    : function(value, data) {
            $.post("myPhPfileWhichBringNumberOfItem.php", { product : value }, function(count) {
                $("#productleft").val(count); // Don't forget to mention an id for the input first
            }
        }
    });
});

Use JQuery post at the moment a value is selected, and then use a php script which open your database, go to the table and select number of product left (not sure if you should use value or data, please someone correct if I am wrong).