I'm using HTML to create checklists through `<input>`. Here's a small sample of my code.

```
<input type="checkbox" value="Expedia" />
<img src="http://cruise360.org/media/ex_logos/3zp4zr1avvnfydluitkn4yur31iveig3172013_111844.jpg" style="width:236px;height:135px;" />
<br />

```

How can I make a javascript variable that is set to 0 or 1 depending on whether the option is checked. For example I'd have something like:

```
if (box is checked..) {
  expediaChecked == 1
} else {
  exediaChecked==0
}

```

How can I connect HTML and Javascript like that? Thank you.