I actually like a combination of Dimitar Christoff answer and Trebla:
Element.implement({
toJSON: function(){
var j = {};
Array.each(this.toQueryString().split('&'),function(a){
var kv = a.split('=')
j[kv[0]] = kv[1]||'';
});
return JSON.encode(j);
}
});
console.log($('formular_support').toJSON());