How to Integrate my web Service/Script to the volusion API

Question

I develop a web service/script in php that retrieve data from my vendor site in json format. i convert that data into XML and pass to my Volusion API for import/Insertion But it just return 1. I don't know why the product is not inserted when i check it in the Volusion admin.

This my API request format. http://tebkq.mvlce.servertrust.com/net/WebService.aspxLogin=mylogin&EncryptedPassword=mypass&Import=Insert

Anyone who knows please help me. My code as under..

<?php
    $file = file_get_contents('dataPro.txt', true);

//  Create the Xml to POST to the Webservice

    $Xml_to_Send = "<?xml version=\"1.0\" encoding=\"utf-8\" ?>";
    $Xml_to_Send .= "<Volusion_API>";
//  $Xml_to_Send .= "<!--";
    $Xml_to_Send .= $file;
//  $Xml_to_Send .= "\"\"";
//  $Xml_to_Send .= "-->";
    $Xml_to_Send .= "</Volusion_API>";

    $url = "http://tebkq.mvlce.servertrust.com/net/WebService.aspxLogin=mylogin&EncryptedPassword=mypass&Import=Insert";

//  Create the Header   

$header  = array(
    "MIME-Version: 1.0",
    "Content-type: text/xml; charset=utf-8",
    "Content-transfer-encoding: text",
    "Request-number: 1",
    "Document-type: Request",
    "Interface-Version: Test 1.4"
);


    //  Post and Return Xml
    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL,$url);
    curl_setopt($ch, CURLOPT_POST, true);
    curl_setopt($ch, CURLOPT_POSTFIELDS, $Xml_to_Send); 
    curl_setopt($ch, CURLOPT_HTTPHEADER, $header);
    $data = curl_exec($ch);

    //  Check for Errors
    if (curl_errno($ch)){
        print curl_error($ch);
    } else {
       curl_close($ch);
    }

   //  Display the Xml Returned on the Browser
    echo $data;
?>