<script language="javascript" runat="server">
   Platform.Load("Core","1");


var payload = '';
var username = 'xxx';
var password = 'yyy';
var endpoint = "https://webservice.s6.exacttarget.com/Service.asmx";
var custkey = 'Training Sergio'
var result;

payload += '<?xml version="1.0" encoding="utf-8"?>';
payload += '<soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">';
payload += '   <soap:Header>';
payload += '      <wsse:Security xmlns:wsse="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-secext-1.0.xsd" soap:mustUnderstand="1">';
payload += '         <wsse:UsernameToken xmlns:wsse="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-secext-1.0.xsd" xmlns:wsu="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-utility-1.0.xsd" wsu:Id="UsernameToken-1">';
payload += '            <wsse:Username>' + username + '</wsse:Username>';
payload += '            <wsse:Password Type="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-username-token-profile-1.0#PasswordText">' + password + '</wsse:Password>';
payload += '         </wsse:UsernameToken>';
payload += '      </wsse:Security>';
payload += '   </soap:Header>';
payload += '   <soap:Body>';
payload += '        <PerformRequestMsg xmlns="http://exacttarget.com/wsdl/partnerAPI" xmlns:ns2="urn:fault.partner.exacttarget.com">';
payload += '            <Action>ClearData</Action>';
payload += '                <Definitions>';
payload += '                  <Definition xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:type="DataExtension">';
payload += '                     <CustomerKey>'+custkey+'</CustomerKey>';
payload += '                  </Definition>';
payload += '                </Definitions>';
payload += '        </PerformRequestMsg>';
payload += '   </soap:Body>';
payload += '</soap:Envelope>';

try {
    result = HTTP.Post(endpoint,"text/xml",payload,["SOAPAction"],["Perform"]);
} catch(e) {
    result = {StatusCode:500,Response:Stringify(e)};
}

  if (result.StatusCode != 200) {
    //Bad response
    Write(Stringify(result));
} else {
    //Good response
    Write(Stringify(result));
}

</script>