function insert() {
// Optional: Show a waiting message in the layer with ID login_response
document.getElementById('insert_response').innerHTML = "Just a second..."
// Required: verify that all fileds is not empty. Use encodeURI() to solve some issues about character encoding.
var dispname= encodeURI(document.getElementById('disp_name').value);
var firstname= (document.getElementById('first_name').value);
var lastname= (document.getElementById('last_name').value);
var gender= (document.getElementById('genderreg').value);
var day= (document.getElementById('day').value);
var month= (document.getElementById('month').value);
var year= (document.getElementById('year').value);
var country= (document.getElementById('countryreg').value);
var city= (document.getElementById('cityreg').value);
var suburb= (document.getElementById('suburbreg').value);
var email= (document.getElementById('emailreg').value);
var password= (document.getElementById('regpassword').value);
var code= (document.getElementById('code').value);
var service= (document.getElementById('termservice').value);

// Set te random number to add to URL request
nocache = Math.random();
// Pass the login variables like URL variable
http.open('get', 'register_insert.php?site_url='+dispname+'&fname= '+firstname+'&lname= '+lastname+'&gender= '+gender
    	  +'&day= '+day+'&month= '+month+'&year= '+year+'&country= '+country+'&city= '+city+'&suburb= '+suburb
    	  +'&email= '+email+'&password= '+password+'&code= '+code+'&service= '+service+'&nocache= '+nocache);
http.onreadystatechange = insertReply;
http.send(null);
}

var fields = {'disp_name', 'first_name', 'last_name', 'genderreg' /* etc ... */ ];
var values = {};
for (var i = 0, l = fields.length; i < l; ++i) {
    values[fields[i]] = document.getElementById(fields[i]).value;
}

http.open(
    'get',
    'register_insert.php'
    + '?site_url=' + values.dispname
    + '&fname=' + values.first_name
    + '&lname=' + values.last_name /* etc */
);