JavaScript Load New Page Question

Question

What I am looking to do is if a user complete a form it will provide access to a new location.

<script language="JavaScript" type="text/javascript">     
<!--     
function validateForm(theForm) {     
 var firstname = theForm.firstname.value; 
 var lastname = theForm.lastname.value;      
 var email = theForm.email.value;     
 if (firstname == "") {     
   alert("Please fill in your First Name.");     
   theForm.firstname.focus();     
   return false;     
 }   
 if (lastname == "") {     
   alert("Please fill in your Last Name.");     
   theForm.lastname.focus();     
   return false;     
 } 

 if (email == "") {     
   alert("Please fill in your email address.");     
   theForm.email.focus();     
   return false;     
 }     
 return true;     
}

I know this part is wrong but I have no idea how to go about doing it. any help would be nice..

 if lastname=""
 if firstname=""
 if email=""
 load('www.google.com');

Answer 1

if (validateForm(theForm)) window.location = 'http://www.google.com';

Is equivalent to using

if (validateForm(theForm)) window.location.href = 'http://www.google.com';

Both will work, so choose which one you prefer.

Answer 2

if lastname=""
if firstname=""
if email=""
load('www.google.com');

becomes

if ((lastname == "") && (firstname == "") && (email == "")) {
    window.location = "http://www.google.com";
}