find all input elements in a form

$("form#formID :input").each(function(){
 var input = $(this); // This is the jquery object of the input, do what you will
});

$("form").submit(function(){ return validateForm($(this)) });
function validateForm(form){
var retVal = true;
var re;
$.each(form.serializeArray(), function(i, field) {
  var input = $('input[name='+field.name+']');
  field.value = $.trim(field.value);
  switch(field.name){
    case "name" :
        and another cases...
      }
    })
 }

Find all input in a form