I need my gravityforms form tag to have an "oninput" in it.

Like so:

```
<form oninput="loanval.value=parseInt(loan.value, 10).toLocaleString('en-US').replace(',', ' ');">

```

I read about the gravity forms hooks, but there not really a lot of documentation and I'm not very experienced with coding. Does anyone know how I can accomplish this?