How can we send a HTTP POST request by using JavaScript?

How can we send a request usin开发者_如何学JAVAg the HTTP POST method via javascript...without submitting a form?

I prefer to use jQuery.post() - for example:

$.post("test.php", function(data){
  alert("Data Loaded: " + data);
});

By using AJAX.

<form id="myform">
<input type="text" name="weather" value="sunny" />
</form>

<a href='javascript:submit_form()'>Click here to submit the form</a>

<script language='javascript'>
function submit_form()
{
   var myform = document.getElementById('myform');
   myform.submit()
}
</script>