Imagino que esta validación debe ser hecha caracter a caracter
email_valido=true;
car_prohibido="@#)(*&^%$#@!~ ";
email_str="
[email protected]";
for (i=1;i<=email_str.length;i++)
for (k=1;k<=car_prohibido.length;k++)
if (email_str.charAt(i)==car_prohibido.charAt(k))
{
email_valido=false;
break;
}
next k
next i
return email_valido;