XMLHttpRequest call not working

[areyesram]

Hi, I'm trying to make a little customization to a SugarCRM-based product and something is not working.

What I'm trying to do in principle is making Purchase Order Numbers editable. That part is working but a side effect is now I have to validate PO Numbers for duplicates. Particularly, I'm trying to call a server-side method directly from JavaScript to keep the FORM from submitting when the PO Number already exists in a different record.
One of the alternatives I'm trying is AJAX. I found a nice example here:
http://www.w3schools.com/PHP/php_ajax_database.asp

It worked in a separate project but when I try to integrate it to SugarCRM, it seems to reject the request (the page I'm calling from JavaScript gets redirected to Home).

This is the code I've got:

The call (it is in the Save button):

<input title="{APP.LBL_SAVE_BUTTON_TITLE}" accesskey="{APP.LBL_SAVE_BUTTON_KEY}" class="button"
	onclick="this.form.action.value='Save'; return TallyEditor.pre_save() && check_form('PurchaseOrderEditView') && check_duplicate(this.form);"
    name="button" value=" {APP.LBL_SAVE_BUTTON_LABEL} " type="submit">

The JavaScript code:

var xmlhttp;

function check_duplicate(form)
{
    return exists(form.po_number_c.value, form.record.value) != 1;
}

function exists(po, id)
{
    xmlhttp = GetXmlHttpObject();
    if (xmlhttp == null)
    {
        window.alert("Browser does not support HTTP Request");
        return 1;
    }
    var url = "modules/PurchaseOrders/dupid.php";
    url = url+"?po=" + po;
    url = url+"&id=" + id;
    url = url+"&sid="+Math.random();
    xmlhttp.open("GET",url,false);
    xmlhttp.send(null);
    if (xmlhttp.responseText == 1)
        window.alert("ID already exists");
    return xmlhttp.responseText;
}

function GetXmlHttpObject()
{
    // IE7+, Firefox, Chrome, Opera, Safari
    if (window.XMLHttpRequest)
        return new XMLHttpRequest();
    // IE6, IE5
    if (window.ActiveXObject)
        return new ActiveXObject("Microsoft.XMLHTTP");
    return null;
}

The PHP code being called (dupid.php):

 <?php
$po = $_GET["po"];
$id = $_GET["id"];

$query = "SELECT po_number FROM purchase_orders" .
         " WHERE po_number = '" . $po . "'" .
         "   AND id != '" . $id . "'" .
         " LIMIT 0,1";
$result = $this->db->query($query, true, "Error retrieving PO Numbers.");
if($result && ($row = $this->db->fetchByAssoc($result)) !== false)
    echo 1;
else
    echo 0;
?>  

The page dupid.php is supposed to respond with a "1" or a "0" in plain text, but instead, it is redirected to the Home page.

Is there something I should know?

BTW: I've also considered using Web Services but I don't know how.

Please help. I'm new to PHP but I've used ASP.NET for several years.

[areyesram]

Good news at last!
I found the answer in a different thread

Apparently, the PHP code to be called from JavaScript must be in the root directory of the application.

Also, I had to add this to run queries:

 require_once('include/entryPoint.php'); 
  

And queries changed from:

 $this->db->query(...); 
  

to:

 $current_user->db->query(...); 
  

Hope this helps someone else.

[crmsiva]

Hi

You can use YAHOO.util.Connect.asyncRequest() for sending http requests. This will simplify the AJAX part of your code also.