The result is twice the input value.
Input >>

Result >>
A copy of the JavaScript functions in the head element:

// sample-4-form-functions.js
// This sample uses getElementById() to find the input areas
// The validation function always returns true

// reset validation function
// always returns true
function validate()
  {
  return true;
  }

// the functions loaded() and changeInput() are the same as in previous samples.
// see the previous examples for the code for these two functions.