I need your help with a random name generator script.

I found this
But I want to change it abit.
On that one is has two first name variables (one each for male and female) but only one last name var, but I wanted male and female first and last names. I tried tweaking it to this:
<script type="text/javascript" language="JavaScript">
<!-- Hide this script from incompatible browsers!
// Programmed By: Michael C. Hundt Copyright08-25-99, mchundt@nglic.com, http://www.cinet.net/~mhundt/
// Permission granted to SimplytheBest.net to feature script in its DHTML script collection
// Courtesy of SimplytheBest.net - http://simplythebest.net/scripts/

var MFname = new Array("Lazy",Freaky","Crazy","Cool","Baby")
var FFname = new Array("Cool","Crazy","Spicy","Baby","Rock","Glam","Fab",Psycho","Super")
var Lname = new Array("Weirdo","Boy","Daddy","Idiot","God","Dude","Nerd","Man")
var FLname = new 
Array("Weirdo","Diva", "Cow","Girl","Chick")
var r=0
var i=0
function RandomName()
r=Math.floor(Math.random() * Lname.length);
if(document.NAMEIT.GENDER.options[1].selected == true)
i=Math.floor(Math.random() * FFname.length);
i=Math.floor(Math.random() * MFname.length);
// Hide this script from incompatible browsers! -->
<table cellspacing="0" cellpadding="0" bordercolor="#95c43d" border="0" bgcolor="#eef9eb" align="center">
            <h4 style="text-align: center;">Cool Slogan Generator</h4>
            <form name="NAMEIT">
                            <td valign="top" align="right"><b><font size="2" face="Arial">Choose <br/>
                            <td valign="top"><font size="2" face="Arial"><select name="GENDER" size="1">
                            <option value="Male">He Says  </option>
                            <option value="Female">She Says</option>
                            </select> </font> </td>
                            <td valign="top" align="right"><b><font size="2" face="Arial"> First Name:</font></b></td>
                            <td valign="top"><font size="2" face="Arial"><input type="text" name="FNAME" size="15"/></font></td>
                            <td valign="top" align="right"><b><font size="2" face="Arial"> Last Name:</font></b></td>
                            <td valign="top"><font size="2" face="Arial"><input type="text" name="LNAME" size="15"/> </font></td>
                <p align="center"><input type="button" name="Button1" value="Create My Slogan" ONCLICK="RandomName()"/></p>
            </center> </td>
<!-- End Random Name Generator -->
but it doesn't work at all! Nothing gets generated

Also how do I get the result to be shown in a separate text box underneath?

I have been reading
this guide most of the day trying to understand how to do this myself but I am new to js and its just going over my head.

Any pointers in the right direction would be greatly appreciated!

Thank you!
S xx