problem linking tripple combo boxes

[monalisa_smile]

I've a problem with linking tripple combo boxes I don't know what's going on but I've in console that there is a problem with line containing the onreadystatechange property of requestobj this the code for ajax :

<script language="javascript">
            var options;
            var requestobj = false;
            
            if(window.XMLHttpRequest) {
                
                requestobj = new XMLHttpRequest();
                requestobj.overrideMimeType("text/xml");
            }
            else if(window.ActiveXObject) {
                
                requestobj = new ActiveXObject("Microsoft.XMLHTTP");
            }
            function getoptions(datasource, src, vlu, optionlist) {                            
                if(vlu!=""){
                    var datasrc = "modules/mod_goods/"+datasource+"?cat="+src+"&comp="+vlu;
                    } else{
                        //alert("src: "+datasource+" cat: "+src);
                        var datasrc = "modules/mod_goods/"+datasource+"?cat="+src;
                    }
                    if(requestobj) {
                    
                        requestobj.open("GET", datasrc, true);
                        requestobj.onreadystatechange = function() {
                        if (requestobj.readyState == 4 && requestobj.status == 200) {
                            var doc  =  requestobj.responseXML;
                            options = doc.getElementsByTagName("option");
                            listoptions(optionlist);
                    }
                    requestobj.send(null);
                }
            }
            }
             function listoptions (optionlist)
      {
        var i;
        var selectControl = document.getElementById(optionlist);
        for (i = 0; i < options.length; i++ )
        {    
            
            val=options[i].getAttribute("value");
            selectControl.options[i] = new Option(options[i].firstChild.data);
        }
    }
    
        </script>

<div id="nifty">
<b class="rtop">
  <b class="r1"></b> <b class="r2"></b> <b class="r3"></b> <b class="r4"></b>
</b>
<center>
<div id="container">
<form action="<?php  $_SERVER['PHP_SELF'] ?>" method="POST">

     <fieldset>
     <p class="parag">Search:</p>
        <table>        
         <tr>
            <td class="attribute-value">Category: </td>
            <td>
                <?php
                    $sel = export_categoryDalc::getAll();
                ?>
                <select name="cat" id="cat" onChange="getoptions('comp.php',this.value, '', 'comp')">
                    <option value="">All</option>
                    <?php
                        
                    foreach($sel as $cat)
                        {
                            echo"<option value='".$cat->id."'>".$cat->category_name."</option>";
                        }    
                    ?>
            </select>
            </td>
        </tr>
         <tr>
            <td class="attribute-value">Company:</td>
            <td>
                <select name="comp" id="comp" onChange="getoptions('good.php', document.getElementById['cat'].value, this.value, 'good')">
                    <option value="">All</option>
                </select>
            </td>
        </tr>        
        <tr>
            <td class="attribute-value">Good: </td>
            <td>
                <select name="good" id="good">
                    <option value="">All</option>        
                </select>
            </td>
        </tr>
        <tr>    
            <td colspan="2" align="right">
            <input type="submit" name="search_goods" value="search" class="search-button" style="width:auto; "> 
            <input type="hidden" name="page" value="goods"  />
            <input type="hidden" name="task" value="search"  />
            </td>
        </tr>
     </table>
     </fieldset>

   </form>
   </div>
   </center>
   <b class="rbottom">
  <b class="r4"></b> <b class="r3"></b> <b class="r2"></b> <b class="r1"></b>
</b>
   </div>

and this ius for xml:

<?php
    
    header("Content-type: text/xml");
         echo '<?xml version="1.0"?>';
        $cat_id = $_GET['cat'];    
    include("../../admin_panel/db.php");

    include("../../configuration.php");

    include("../../admin_panel/components/zad/dalcs/dalc.php");
        include("../../admin_panel/components/zad/dalcs/class.goods.php");
            
        $comp = export_goodsDalc::getCompany($cat_id);
?>
<options>
    <option value="">All</option>
<?php
            foreach ($comp as $value)
            {
                echo '<option value="'.$value->company_id.'">';
                echo $value->company_name;
                echo '</option>';
            }
?>
</options>

[fahlyn]

you should very seriously consider using prototype.js instead of writing your own ajax javascript. Prototype provides a very nice wrapper for ajax...and it prevents you from having to re-invent the wheel.

Switching to prototype may fix your problem.

[Lop]

you should very seriously consider using prototype.js instead of writing your own ajax javascript. Prototype provides a very nice wrapper for ajax...and it prevents you from having to re-invent the wheel.

Switching to prototype may fix your problem.

Wow, that is a nice little class! I'm going to use that in my next AJAX client (given that I make one). JSON looks pretty neat as well. Never heard of it until now.

[fahlyn]

Personally, I very much prefer JSON to XML when using Ajax. it completely removes the need to parse XML in JavaScript. Glad you like it.