I always forget the exact syntax and waste time searching for an example on the web.
1: $.ajax({
2: type: "POST",
3: url: "Default.aspx/WebMethodWithParameters",
4: data: { param1: $('#val1').val(),
5: param2: $('#val2').val(),
6: param3: $('#val3').val()
7: },
8: success: function(msg) {
9: //on success callback
10: },
11: error: function(msg){
12: //on error callback
13: }
14: });