JavaScript - problemas con java en firefox

Hola a todos, tengo un problema y necesito ayuda. tengo una pagina con un cuadro de subscripcion donde la gente deja su telefono, email, pais, y nombre con el script de java q tengo y bajo explorer cuando no estan rellenos los campos no deja pasar a la siguiente pantalla pero con firefox no funciona, dejo aqui una parte del archivo a ver si alguien me ayuda, gracias...

<script language='JavaScript' type="text/javascript">
var Prototype = {
Version: '1.4.0',
ScriptFragment: '(?:<script.*?>)((\n|\r|.)*?)(?:<\/script>)',

emptyFunction: function() {},
K: function(x) {return x}
}

var Class = {
create: function() {
return function() {
this.initialize.apply(this, arguments);
}
}
}

var Abstract = new Object();

Object.extend = function(destination, source) {
for (property in source) {
destination[property] = source[property];
}
return destination;
}

Object.inspect = function(object) {
try {
if (object == undefined) return 'undefined';
if (object == null) return 'null';
return object.inspect ? object.inspect() : object.toString();
} catch (e) {
if (e instanceof RangeError) return '...';
throw e;
}
}

Function.prototype.bind = function() {
var __method = this, args = $A(arguments), object = args.shift();
return function() {
return __method.apply(object, args.concat($A(arguments)));
}
}

Function.prototype.bindAsEventListener = function(object) {
var __method = this;
return function(event) {
return __method.call(object, event || window.event);
}
}

Object.extend(Number.prototype, {
toColorPart: function() {
var digits = this.toString(16);
if (this < 16) return '0' + digits;
return digits;
},

succ: function() {
return this + 1;
},

times: function(iterator) {
$R(0, this, true).each(iterator);
return this;
}
});

var Try = {
these: function() {
var returnValue;

for (var i = 0; i < arguments.length; i++) {
var lambda = arguments[i];
try {
returnValue = lambda();
break;
} catch (e) {}
}

return returnValue;
}
}

/*--------------------------------------------------------------------------*/

var PeriodicalExecuter = Class.create();
PeriodicalExecuter.prototype = {
initialize: function(callback, frequency) {
this.callback = callback;
this.frequency = frequency;
this.currentlyExecuting = false;

this.registerCallback();
},

registerCallback: function() {
setInterval(this.onTimerEvent.bind(this), this.frequency * 1000);
},

onTimerEvent: function() {
if (!this.currentlyExecuting) {
try {
this.currentlyExecuting = true;
this.callback();
} finally {
this.currentlyExecuting = false;
}
}
}
}

/*--------------------------------------------------------------------------*/

function $() {
var elements = new Array();

for (var i = 0; i < arguments.length; i++) {
var element = arguments[i];
if (typeof element == 'string')
element = document.getElementById(element);

if (arguments.length == 1)
return element;

elements.push(element);
}

return elements;
}
Object.extend(String.prototype, {
stripTags: function() {
return this.replace(/<\/?[^>]+>/gi, '');
},

stripScripts: function() {
return this.replace(new RegExp(Prototype.ScriptFragment, 'img'), '');
},

extractScripts: function() {
var matchAll = new RegExp(Prototype.ScriptFragment, 'img');
var matchOne = new RegExp(Prototype.ScriptFragment, 'im');
return (this.match(matchAll) || []).map(function(scriptTag) {
return (scriptTag.match(matchOne) || ['', ''])[1];
});
},

evalScripts: function() {
return this.extractScripts().map(eval);
},

escapeHTML: function() {
var div = document.createElement('div');
var text = document.createTextNode(this);
div.appendChild(text);
return div.innerHTML;
},

unescapeHTML: function() {
var div = document.createElement('div');
div.innerHTML = this.stripTags();
return div.childNodes[0] ? div.childNodes[0].nodeValue : '';
},

toQueryParams: function() {
var pairs = this.match(/^\??(.*)$/)[1].split('&');
return pairs.inject({}, function(params, pairString) {
var pair = pairString.split('=');
params[pair[0]] = pair[1];
return params;
});
},

toArray: function() {
return this.split('');
},

camelize: function() {
var oStringList = this.split('-');
if (oStringList.length == 1) return oStringList[0];

var camelizedString = this.indexOf('-') == 0
? oStringList[0].charAt(0).toUpperCase() + oStringList[0].substring(1)
: oStringList[0];

for (var i = 1, len = oStringList.length; i < len; i++) {
var s = oStringList[i];
camelizedString += s.charAt(0).toUpperCase() + s.substring(1);
}

return camelizedString;
},

inspect: function() {
return "'" + this.replace('\\', '\\\\').replace("'", '\\\'') + "'";
}
});

String.prototype.parseQuery = String.prototype.toQueryParams;

var $break = new Object();
var $continue = new Object();

var Enumerable = {
each: function(iterator) {
var index = 0;
try {
this._each(function(value) {
try {
iterator(value, index++);
} catch (e) {
if (e != $continue) throw e;
}
});
} catch (e) {
if (e != $break) throw e;
}
},

all: function(iterator) {
var result = true;
this.each(function(value, index) {
result = result && !!(iterator || Prototype.K)(value, index);
if (!result) throw $break;
});
return result;
},

any: function(iterator) {
var result = true;
this.each(function(value, index) {
if (result = !!(iterator || Prototype.K)(value, index))
throw $break;
});
return result;
},