alert a variable value

Question

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") {    new=inputs[i].getAttribute("value"));  alert(new)    } } 

Answer 1

Note, while the above answers are correct, if you want, you can do something like:

alert("The variable named x1 has value:  " + x1);