How to get old Value with onchange() event in text box

Question

I have a text Box and a Value poplulated in it when page loads. Now If user chanegs any thing in text box, then I want to get the Changed Value(New Value) and Old Value but

Answer 1

I would suggest:

function onChange(field){
  field.old=field.recent;
  field.recent=field.value;

  //we have available old value here;
}