Create a dynamic URL with parameter?

[JAB Creations]

I'm trying to create a dynamic URL passing on a parameter, here is what I have...

Page Function

contact_artist(law);

Main Script

function contact_artist(artist) {
var ajax_this = 'includes/contact-email.php?nameis=' + artist;
ajaxpage(ajax_this, 'promptsajax');
}

I would like to have the script create a URL of...

includes/contact-email.php?nameis=law

...in this example. What am I doing incorrectly?

[jscheuer1]

contact_artist('law');

[JAB Creations]

A thank you to you sir!