//calculates percent increase or decrease compared to BASELINE_STUDY_EVENT
//adjust the first four variables

var BASELINE_STUDY_EVENT = 'Screening';  //study event name associated with the baseline form
var BASELINE_FORM = "Baseline Form"; //baseline form name
var BASE_ITEM_NAME = 'AverageSys'; //baseline item name to be compared 
var THIS_ITEM_NAME = 'AverageSys'; //the name of the current item
var ret = null;

    var baseForms = findFormData(BASELINE_STUDY_EVENT, BASELINE_FORM);              //find the baseline form
    if (baseForms !== null && baseForms.length === 1) {                             //if the form exists perform the following 
        var baselineSum = findFirstItemValueByName(baseForms[0], BASE_ITEM_NAME);   //find the baseline item value
        var thisFormSum = findFirstItemValueByName(formJson, THIS_ITEM_NAME);       //find the value of the current item
        if (!isNaN(baselineSum) && !isNaN(thisFormSum)) {                           //ensure neither value is null
            ret = ((Number(thisFormSum) - Number(baselineSum)) / Number(baselineSum))*100; //perform the calculation... ((current - baseline)/baseline)*100
        }
    }

return ret;