[jQuery] Validate textbox on selected value in a combobox

[ciupaz]

Hello,
how can I validate several textbox basing on selected combobox?
For example, having this combo:

<select id="mySelect" name="mySelect">
      <option value="-1">Please select</option>
      <option value="1">CA</option>
       <option value="2">PR</option>
       <option value="3">PROV</option>
</select>

I'd like to make required the first textbox if the user select the
first value, and so on.


<input id="myFirstInput" name="myFirstInput" type="text" />
<input id="mySecondInput" name="mySecondInput" type="text" />
<input id="myThirdInput" name="myThirdInput" type="text" />

I have to change my validate plugin:

myFirstInput: {
                    required: true // to complete
               }


but I've not found the correct way.

Has anyone ideas?

Thanks a lot.

Luigi