var $$ = window.Dom7;
//do get request
$$.get('path-to-file.php', {id:3}, function (data) {
  consol.log(data);
}

//do post request
$$.post('path-to-file.php', {id:3}, function (data) {
  consol.log(data);
}

//get JSON request
$$.getJSON('path-to-file.js', function (json) {
  consol.log(json);
}