Content is not allowed in prolog

[fisad]

I try php code attached (tree_source.php), but, in Flex Builder 3 application,
line 43:

<mx:XML id="dp" source="data/tree_source.php" />

Flex show the error:

"Problem parsing external XML: C:\xampp\htdocs\Tree
Gallery\src\data\tree_source.php - (line 43) Content is not allowed in prolog."

??? Any help me, please.

Thnak in advance

tree_source.php
--------------------------------------------------
<?php
$path = "images";

echo '<?xml version="1.0" encoding="UTF-8"?>' . "\n";
echo "<root>"."\n";

structure($path,$path);

echo "</root>";


// Function
function structure($rootdirpath,$dir)
{
unset($root);
if($dp = @opendir($rootdirpath))
{
for($i=0;($file=readdir($dp))!==false;$i++)
{
if (is_dir($rootdirpath."/".$file) && $file != "." && $file != "..")
{
echo "<node label=\"".$file."\">"."\n";
structure($rootdirpath."/".$file,$dir);
echo "</node>\n\r";
}
}
}
closedir($dp);
}

?>
------------------------------------------------

Flex Builder 3 code:
------------------------------------------------------
<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
layout="absolute"
width="100%" height="100%">

<mx:Script>
<![CDATA[
import mx.events.ListEvent;
import mx.collections.ICollectionView;
import mx.events.ListEvent;

private function tree_itemClick(evt:ListEvent):void {
var t:Tree = evt.currentTarget as Tree;
var dataObj:Object = evt.itemRenderer.data;

var item:Object = Tree(evt.currentTarget).selectedItem;
if (tree.dataDescriptor.isBranch(item)) {
tree.expandItem(item, !tree.isItemOpen(item), true);
}

if (dataObj.hasOwnProperty("@src")) {
swfLoader.source = dataObj.@src;
} else if (t.dataDescriptor.isBranch(t.selectedItem)) {
swfLoader.source = null;
panel.status = "";
}
}

private function tree_labelFunc(item:Object):String {
var suffix:String = "";
if (tree.dataDescriptor.isBranch(item)) {
suffix = " (" + item.children().length() + ")";
}
return item.@label + suffix;
}

private function swfLoader_complete(evt:Event):void {
panel.status = (swfLoader.bytesTotal/1024).toFixed(2) + 'KB';
}
]]>
</mx:Script>

<mx:XML id="dp" source="data/tree_source.php"></mx:XML>

<mx:HDividedBox width="100%" height="100%" horizontalCenter="12"
verticalCenter="12">
<mx:Panel width="200" height="100%">
<mx:Tree id="tree"
dataProvider="{dp}"
labelFunction="tree_labelFunc"
showRoot="false"
width="100%"
height="100%"
itemClick="tree_itemClick(event);" />
</mx:Panel>
<mx:Panel id="panel"
width="100%"
height="100%"
backgroundColor="white">
<mx:SWFLoader id="swfLoader"
scaleContent="true"
width="100%"
height="100%"
complete="swfLoader_complete(event);" horizontalAlign="center"
verticalAlign="middle"/>
<mx:ControlBar>
<mx:LinkButton label="{swfLoader.source.toString()}" />
</mx:ControlBar>
</mx:Panel>
</mx:HDividedBox>

</mx:Application>
-----------------------------------------------------

[levancho]

execute this : C:\xampp\htdocs\Tree Gallery\src\data\tree_source.php
in your browser and make sure xml has no spaces or some other chars on top, or somewhere else, it must be well formed xml.

[fisad]

I execute code in browser and don't show has no spaces or some other chars
somewhere, I saved with notepad in correct format but nothing.

I have following code for create xml file with php, this xml file read correct
in Flex:

-------------------------------------
<?php
$path = "images";

$fp=fopen("data/tree_source.xml","w");
fwrite($fp,'<?xml version="1.0" encoding="UTF-8"?>' . "\n");
fwrite($fp,"<root>"."\n");

structure($path,$fp,$path);

fwrite($fp,"</root>");
fclose($fp);


// Function
function structure($rootdirpath,$fp,$dir)
{
unset($root);
if($dp = @opendir($rootdirpath))
{
for($i=0;($file=readdir($dp))!==false;$i++)
{
if (is_dir($rootdirpath."/".$file) && $file != "." && $file != "..")
{
fwrite($fp,"<node label=\"".$file."\">"."\n");
structure($rootdirpath."/".$file,$fp,$dir);
fwrite($fp,"</node>\n\r");
}

}
}
closedir($dp);

}


?>
------------------------------

I need know how execute this code from Flex at any time for refresh contens of
tree, one at start application, other when de directory structure has changed.

Any example code for help me, please.

Thank in advance-