Should I send additional headers with HmlHttpRequest POST?

[shapeshifter6161]

After opening XmlHttpRequest POST connection\[code\]var http = new XMLHttpRequest();http.open("POST", url, true);\[/code\]Some recommend to include these additional headers before sending the request:\[code\]http.setRequestHeader("Content-type", "application/x-www-form-urlencoded");http.setRequestHeader("Content-length", params.length);http.setRequestHeader("Connection", "close");\[/code\]Is it necessary on Apache+PHP server? It works fine on my server without those headers.