you can use following code :
var form = new FormData($('#form_step4')[0]);
form.append('view_type','addtemplate');
$.ajax({
type: "POST",
url: "savedata.php",
data: form,
cache: false,
contentType: false,
processData: false,
success: function(data){
//alert("---"+data);
alert("Settings has been updated successfully.");
window.location.reload(true);
}
});
where savedata.php is the file name in which you can do the the DB things