A ver si algo así te sirve...
<!-- PRIMER PASO: Copiar dentro del tag HEAD -->
<script LANGUAGE="JavaScript">
<!--
function Del(Word) {
a = Word.indexOf("<");
b = Word.indexOf(">");
len = Word.length;
c = Word.substring(0, a);
if(b == -1)
b = a;
d = Word.substring((b + 1), len);
Word = c + d;
tagCheck = Word.indexOf("<");
if(tagCheck != -1)
Word = Del(Word);
return Word;
}
function Check() {
ToCheck = document.form.text.value;
Checked = Del(ToCheck);
document.form.text.value = Checked;
return true;
}
// -->
</script>
<!-- SEGUNDO PASO: Copiar el formulario dentro del tag BODY -->
<form action="http://www.tu-sitio.com/cgi-bin/enviar.cgi" name="form"
onSubmit="return Check()">
<div align="left"><p><textarea cols="20" rows="3" name="text"></textarea> <br>
<input type="submit" value="Enviar"> </p>
</div>
</form>