Script anti spam in tagboard

<script type="text/javascript">
//Creato da Ltk_Sim per il NewsBoard Forum
var mexnospam = 'Non puoi inserire links esterni in Tag!'
urlAllowed = new Array();
urlAllowed [0]="example.forumfree.net";
urlAllowed [1]="supporto.forumfree.net";
urlAllowed [2]="newsboard.forumfree.net";
urlAllowed [3]="google.com";
var tagboardv = document.tagboard ? document.tagboard : 0;
if(tagboardv) {
function noSpam() {
var content = tagboardv.ffmsg.value.toLowerCase();
if(content.indexOf("http://") != -1 || content.indexOf("www") != -1)
{
var x=0;
var arrayn = urlAllowed.length;
while(x<arrayn)
{
if(content.indexOf(urlAllowed[x]) != -1)
{
return true;
}
else{
if (x==arrayn-1)
{
alert(mexnospam);
return false;
}
x++;
}
}
}
}
tagboardv.onsubmit = noSpam;
tagboardv.ffmsg.onkeypress = function(e)
{
tagboardv.rem.value=300-tagboardv.ffmsg.value.length;
var submittag = tagboardv.elements;
for(i=0;i<submittag.length;i++)
{
var ind = new function() {this.i = i;}
if(submittag[ind.i].value == "Invia")
{
var submittag = submittag[ind.i];
}
}
valueKey=(isNav) ? e.which : window.event.keyCode;
if(valueKey==13 && (parseInt(tagboardv.rem.value)>=1) ) {
submittag.click();
}
}
}
</script>