Adding a small javascript file to functions.php

I want to use Hostgator's javascript validator to validate simple forms using WordPress. This is the code I've put in the functions.php of a genesis child theme.

function hgformcode() {
echo '<script type="text/javascript" src="hgformcode.js"></script>';
}

add_action('wp_head', 'hgformcode');

I put the Hostgator javascript file in the child theme folder. I called it hgformcode.js

This is the Hostgator javascript validator.

function hgsubmit()
{
if (/\S+/.test(document.hgmailer.name.value) == false) alert ("Please provide your name.");
else if (/^\S+@[a-z0-9_.-]+\.[a-z]{2,6}$/i.test(document.hgmailer.email.value) == false) alert ("A valid email address is required.");
else if (/\S+/.test(document.hgmailer.comment.value) == false) alert ("Your email content is needed.");
else {
document.hgmailer.submit();
alert ('Thank you!\nYour email is sent.');
}
}

I'm doing this to avoid maintenance by not using a form plugin. I only want one form on the site.

This works but is it safe?

Thanks for your help
Philip.