This Web page prompts visitors for their age. Once the age is entered, it is sent to a JavaScript function located in the head of the Web page. If the age is less than sixteen, the function creates a response appropriate for that age. The response is displayed below:

Welcome!

Here's the code used to create the function in the head section of the Web page:

<script language="Javascript" type="text/javascript">

function checkage(age)
{
window.document.write("Welcome! ");

if (age<=16)
{
window.document.write("You're a young one!");
}

}
</script>

Here's the code used to prompt users for their age (located in the body of the document):

<script language="Javascript" type="text/javascript">

//declare variable to capture age of user
var age;

//ask users how old they are
age=prompt("How old are you?", "");

</script>
comparison operators
== is equal
!= is different
< is less than
<= is less than or equal
>= is equal or greater than
> is greater than