<form id="ff"> 
  <input type="text" name="test1"/> 
  <input type="text" name="test2"/> 
  <input type="text" name="test3"/> 
  <input type="text" name="test4"/> 
  <input type="button" id="save" value="save"/> 
</form> 

$("#save").on("click", function () { 
 var params = $("#ff").serializeArray(); 
 var j = {}; 
 for (var item in params) { 
   j[params[item].name] = params[item].value; 
 } 

 $.ajax({ 
   url:'index.html', 
   data:JSON.stringify(j), 
   type:'post', 
   dataType:'json', 
   headers:{ 
 Accept:"application/json", 
 "Content-Type":"application/json" 
   }, 
   processData:false, 
   cache:false 
 }).done(function (data) { 
 }); 

});