Can a boolean be set up to find the max value?

Press Ctrl+J and check if there are any error messages.

Also, you have to change the value of one of the fields in the file for it to "kick in".

What happens when you use the function?

This code was originally written to calculate an average value. I see that you changed it, but you should not edit code unless you know what you're doing...

I've made the adjustments for you. Try this version:

/*
  @params
        aFields : an array of the field names to use for the calculation
        bIgnoreBlanks : a boolean that tells the function whether or not to ignore blank fields
        bIgnoreZeros : a boolean that tells the function whether or not to ignore zero values
*/
function calcMax(fields, ignoreBlanks, ignoreZeros) {
    var max = -Infinity;
    for (var i in fields) {
        var f = this.getField(fields);
        if (f==null) {
            console.println("Error! Can't locate a field called: " + fields);
            continue;
         }
         if (f.valueAsString=="" && ignoreBlanks) continue;
         var v = Number(f.valueAsString);
         if (isNaN(v)) continue;
         if (v==0 && ignoreZeros) continue;
         if (v>max) max = v;
     }
     if (max==-Infinity) event.value = "";
     else event.value = max;
}

Also, what does a boolean value have to do with it?