Need dropdown fields to populate checkbox (Yes, No)

[Guest]

My customer has a form with a Checkbox field called "WeekendCare" With options "Yes" and "No" 

I have 8 dropdown fields (Weekend open and close times) that will need to be examined to determine whether to populate the yes/no. If ANY of the following 8 dropdown fields have a value of a time in the dropdown (other than the default "Select") - the Weekend Care gets checked "Yes"  - if none have values, then "No" is checked.

The dropdown fields are named:

CenterOpenSaturday

CenterOpenSaturday2

CenterCloseSaturday

CenterCloseSaturday2

CenterOpenSunday

CenterOpenSunday2

CenterCloseSunday

CenterCloseSunday2

Can you help with a javascript for this?

And please let me know which field to place the javascript in... that is confusing sometimes.

Thanks for your help!

[try67]

Yes, this kind of operation can be quite tricky. I think the best was of doing it is to create a hidden text field and use its calculation event for this task, even if the field itself has nothing to do with it. You can use this code to achieve it:

var dropdowns = [
    "CenterOpenSaturday", "CenterOpenSaturday2", "CenterCloseSaturday", "CenterCloseSaturday2", "CenterOpenSunday", "CenterOpenSunday2", "CenterCloseSunday", "CenterCloseSunday2"
];
var tickBox = false;
for (var i in dropdowns) {
    var f = this.getField(dropdowns);
    if (f.valueAsString!=f.defaultValue) {
        tickBox = true; break;
    }
}
this.getField("WeekendCare").checkThisBox(0, tickBox);