getInputs - collects and serialize all tag fields (input,textarea,select) into jQuery object or JSON format.

getInputs.js

// prerequisites: jQuery library.

getInputs = function(t,f){
	var opt = typeof t==="object" && t || {};
	var target = opt.target || (t===jQuery || typeof t==="string") && t;
	var filter = opt.filter || f;
	var A = {
		serialized: {},
		fields: $("input,textarea,select", target || document)
	};
	A.fields = filter && A.fields.filter(filter) || A.fields;
	A.fields.each(function(i,k){
		var f = $(this).attr('name') || $(this).attr('id');
		var val = $(this).val();
		if(opt.clean && !val) { return null; }
		if(this.type && (this.type=="checkbox" || this.type=="radio") && !this.checked) { f = null; }
		if(f) {
			if(f.match(/\[\]$/g)) {
				var fa = f.replace("[]","");
				if(!(A.serialized[fa] instanceof Array)) {
					A.serialized[fa] = [];
				}
				A.serialized[fa].push(val);
			}
			else {
				A.serialized[f] = val;
			}
		}
	});
	A.json = A.serialized;
	return A;
};

// collect all document inputs and use as json format
var json_fields = getInputs().json;
if(fields.email) {
    // logic here...
}

// collect and use jQuery objects
var jquery_fields = getInputs().fields;
if(jquery_fields.length) {
   // logic
}

// use selector to collect inputs
var fields = getInputs("form#save_info").json;
$.post("/save/profile", fields);

// use selector (with filter) to collect inputs 
// -- collects only fields with 'rel' attributes: <select rel='..'> <input rel='...'> , etc...
var fields = getInputs("form#save_info","[rel=required]").json;
$.post("/save/profile", fields);