You can try this:
$.ajax({
url: "test.html",
cache: false,
success: function(html){
$("#results").append(html);
}
});
This code will append the content of test.html
file to #results
element
You can find more information at jQuery website.
Update:
Use this code to send POST data and output result.
var menuId = $("ul.nav").first().attr("id");
var request = $.ajax({
url: "script.php",
type: "POST",
data: {id : menuId},
dataType: "html"
});
request.done(function(msg) {
$("#log").html( msg );
});
request.fail(function(jqXHR, textStatus) {
alert( "Request failed: " + textStatus );
});