static function sendXmlHttpResponseHeaders($contenttype = "application/json", $charset = 'utf-8')
	{
		if ( is_null($charset) )
			$charset = mb_internal_encoding();
			
		// charset
		header("Content-Type: $contenttype; charset=$charset");
		
		// no cache
		header("Expires: Sat, 1 Jan 2005 00:00:00 GMT");
		header("Last-Modified: ".gmdate( "D, d M Y H:i:s")." GMT");
		header("Cache-Control: no-cache, must-revalidate");
		header("Pragma: no-cache");	
	}
static function sendXmlHttpResponseHeaders($contenttype = "application/json", $charset = 'utf-8')
	{
		if ( is_null($charset) )
			$charset = mb_internal_encoding();
			
		// charset
		header("Content-Type: $contenttype; charset=$charset");
		
		// no cache
		header("Expires: Sat, 1 Jan 2005 00:00:00 GMT");
		header("Last-Modified: ".gmdate( "D, d M Y H:i:s")." GMT");
		header("Cache-Control: no-cache, must-revalidate");
		header("Pragma: no-cache");	
	}
static function sendXmlHttpResponseHeaders ( $ contenttype = "application/json" , $ charset = 'utf-8' ) { if ( is_null ( $ charset ) ) $ charset = mb_internal_encoding ( ) ; // charset header ( "Content-Type: $contenttype; charset=$charset" ) ; // no cache header ( "Expires: Sat, 1 Jan 2005 00:00:00 GMT" ) ; header ( "Last-Modified: " . gmdate ( "D, d M Y H:i:s" ) . " GMT" ) ; header ( "Cache-Control: no-cache, must-revalidate" ) ; header ( "Pragma: no-cache" ) ; }
Output http headers suitable for xmlhttp

@param string $contenttype Content-type to output
@param string $charset Charset of content
Output http headers suitable for xmlhttp