encodeURIComponent instead of utf8_encode

Changing `utf8_encode()` to `encodeURIComponent()` may solve all the encoding issues.

e.g.

```
javascript:alert(encodeURIComponent("Çáåøn"));
javascript:alert(decodeURIComponent("%C3%87%C3%A1%C3%A5%C3%B8n"));
```

Need PHP implementation of `encodeURIComponent()`.
