[OklickSpb]

Все, разобрался, спасибо.

var name = document.getElementById("AdvertEditNameInput").value;       
        var send_post="name=" + name; 
        xmlHttp.open("POST", "./action/pagein/editAdvertName.php", true); 
	    xmlHttp.setRequestHeader("Content-Type","application/x-www-form-urlencoded");
	    xmlHttp.onreadystatechange = handleRequestStateChange_AdvertEditType; 
	    xmlHttp.send(send_post);