Javascript：onchange无法正常工作

Question

I want to change my HTML page based on some input. So I tried using javascript event handlers to achieve this. But they doesn't seem to work at all. Here's my code:

var nam = document.getElementById('FNAME');
nam.onchange=test();
function test(){
alert("test");
}

This only works for one time when the page loads.

I've included this external javascript file in my HTML code just before closing the body tag.

Answer 1

This only works for one time when the page loads.

No. It doesn't work even when the page loads for the first time. It's just that you're getting an alert due to the invocation of test .

onchange expects a function reference, which it will invoke when it's associative event is triggered. So you should be doing

nam.onchange = test; // don't call it, just pass the reference.

Answer 2

There are two more easy ways (except function reference):

nam.onchange = function(){
    alert("test");
}

or

nam.onchange = function(){
    test();
}

up to you