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Question

I am making an online issue system in PHP.However,for updating the data,I need to pass a JS variable to PHP using AJAX and am not able to do so.Here is the code.

  <?php   
     

    $sql=mysql_query("SELECT * FROM techroom ORDER BY Id DESC");

 
    while($row=mysql_fetch_assoc($sql)){
 

      
        echo "<tr><th>{$row['Id']}</th>";
      
        echo "<th>{$row['Item']}</th>"; 
        echo "<th> {$row['Description']}</th>";
        echo "<th>{$row['Quantity left']}</th>";
      
        echo '<th><button id="issue'.$row['Id'].'" onclick="issue('.$row['Id'].')">Issue</button></th></tr>';
      
      
        }
        ?>

Here is the JS function and AJAX code:

<script>
function issue(id){    
   
  var quantity=prompt("Quantity required?");
  if(quantity!=null){
   var n= prompt("No. of days required");
   if(n<=10){
        $.ajax(
{
    type: "POST",
    url: "/tech.php",
    data: quantity,id,
    success: function(data, textStatus, jqXHR)
    {
        console.log(data);
    }
});        
     }
    else{
      confirm("Max. limit is 10 days");
    } 
   }
      
}
</script>

And here is the file I want to direct to:

<?php
include "header.php";
include "mysql_connect.php";
$id=mysql_real_escape_string(strip_tags($_POST("id")));
$q=mysql_real_escape_string(strip_tags($_POST("q")));
$sql=mysql_query("SELECT * FROM techroom ORDER BY Id DESC");
     while($row=mysql_fetch_assoc($sql)){
      mysql_query("UPDATE techroom SET $row['Quantity left']=$row['Quantity left']-$q WHERE $row['Id']=$id");
    }
   ?>

Please correct me where I am wrong as I am doing this for the first time.

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