Looking for some help on whether there's a smarter way I can make my form work, using arrays.

I have a form where you either need to enter details of a person's weekly, fortnightly or monthly salary and overtime. If you enter a weekly basic salary, I want to disable all the fortnightly and monthly salary and overtime fields.

In my HTML each field has a name e.g. 

And my javascript so far for disabling fields is:

```
if (document.getElementById("basic_sal_weekly").value >0) { 
    document.getElementById("basic_sal_fortnightly").disabled=true;
    document.getElementById("basic_sal_4weekly").disabled=true;
    document.getElementById("basic_sal_monthly").disabled=true;
} else {
   document.getElementById("basic_sal_fortnightly").disabled=false;
}

```

However I'm sure there's got to be a quicker way of doing this, than manually typing out every single field in my HTML document.