alert a variable value

How do I display the value of a variable in javascript in an alert box?

For example I’ve got a variable x=100 and alert(x) isn’t working.

the script used in grease monkey is here

var inputs = document.getElementsByTagName('input');

var new;
for (i=0; i<inputs.length; i++) {
  if (inputs[i].getAttribute("name") == "ans") {   




A couple of things:

  1. You can’t use new as a variable name, it’s a reserved word.
  2. On input elements, you can just use the value property directly, you don’t have to go through getAttribute. The attribute is “reflected” as a property.
  3. Same for name.


var inputs, input, newValue, i;

inputs = document.getElementsByTagName('input');
for (i=0; i<inputs.length; i++) {
    input = inputs[i];
    if ( == "ans") {   
        newValue = input.value;