Preventing urls containing specified words ?

[mattc_uk]

Is there a way of preventing url's containing specified words being submitted in a html form ?

i.e. if a user attempts to submit a form with the word "casino" anywhere in the url field, a message is returned.

At the moment I only have a check that the field cannot be empty as shown below..

if (document.addurl.url.value == "") {
alert("Please specify a url")
document.addurl.url.focus();
return false;

Cheers
Matt

[Scriptage]

You can use indexOf("casino") to check for the word...

I'd use an array and an iterator ie:

words[0]="casino";
words[1]="poker";
words[2]="cards";

for(var i=0; i<words.length; i++){

if(document.addurl.url.indexOf(words[i]) != -1){
alert("Invalid url");
return false;
}

}

[mattc_uk]

Thanks for the info. Im having problems using it in this funciton as follows...

[I]<script language="javascript">

function valData () {

words[0]="casino";
words[1]="poker";
words[2]="cards";

for(var i=0; i<words.length; i++){

if(document.addurl.url.indexOf(words) != -1){
alert("Invalid url");
return false;
}
if (document.addurl.website.value == "") {
alert("Please specify your website name")
document.addurl.website.focus()
return false
}
if (document.addurl.recip_url.value == "") {
alert("Please specify where your reciprocal link url will be")
document.addurl.recip_url.focus();
return false;
}
}
</script>
<SCRIPT TYPE="text/javascript">
<!--
function checkEmail(email)
{
if(email.length > 0)
{
if (email.indexOf(' ') >= 0)
alert("email addresses cannot have spaces in them");
else if (email.indexOf('@') == -1)
alert("a valid email address must have an @ in it");
}
}
//-->
</SCRIPT>

Any ideas?

[konithomimo]

just use the .match method:

var myurl = document.addurl.url.value; 
if (myurl == "") {
alert("Please specify a url")
document.addurl.url.focus();
return false;
}
if(myurl.match('casino'))
{
alert('That is an invalid URL')
return false;
}

And if you want to check for multiple words then just put them inside of an array:

<script type="text/javascript">
function changeThem()
{
var mywords = new Array('casino','cards','poker');
var myurl = document.getElementById('ads').value.toLowerCase(); 
var i, word;
if (myurl == '') 
{
alert("Please specify a url")
document.addurl.url.focus();
return false;
}

for(i=0;i<mywords.length;i++)
{
if(myurl.match(mywords[i]))
{
alert('That is an invalid URL. The word ' + mywords[i] + ' cannot be used in the URL.');
return false;
}}}

just add whatever words you want to the array. In the script I changed every input to lowercase so that you don't need multiple inclusions for one word.