Datumfeld

const dateFieldID   = '640'; // Visforms date field ID of field list const selectFieldID = '641'; // Visforms select field ID of field list jQuery(document).ready(function() {     console.log('FEWA script loaded');     jQuery('.visform').bind('visformsInitialised', function() {         // start after form is initialized         console.log('visformsInitialised');         // hide listbox-age control group         jQuery(`div.field${selectFieldID}`).css('display', 'none');         jQuery(`#field${dateFieldID}`).on('change', function() {             let value = jQuery(this).val();             // no date selected: deselect listbox and quitt             if('' === value) {                 console.log('no date selected');                 jQuery(`#field${selectFieldID} option`).prop('selected', false);                 jQuery(`#field${selectFieldID}`).trigger("change");                 return;             }             // date selected: verify the age             let verify  = 18;             let reached = minage(value, null, {minage : verify});             console.log(value + ` - reached ${verify}: ` + reached);             if(reached) {                 jQuery(`#field${selectFieldID}`).val(1);             }             else {                 jQuery(`#field${selectFieldID}`).val(0);             }             jQuery(`#field${selectFieldID}`).trigger("change");         });     }); }); function minage(value, element, options) {     let check = false, minage = "", age = "", format, i = 0, fmt = {}, valueParts, years, now = new Date();     // a date is selected     if (value) {         // no minage set         if (options.minage) {             minage = options.minage;         } else {             return true;         }         // get year, month and day from selected date         // with regards to the currently used format         format = (value.indexOf(".") > -1) ? "dd.mm.yyyy" : ((value.indexOf("/") > -1) ? "mm/dd/yyyy" : "yyyy-mm-dd");         format.replace(/(yyyy|dd|mm)/g, function (part) {             fmt[part] = i++;         });         valueParts = value.match(/(\d+)/g);         value = new Date(valueParts[fmt["yyyy"]], valueParts[fmt["mm"]] - 1, valueParts[fmt["dd"]], 0, 0, 0, 0);         // get the difference between the year of now and the selected date         years = now.getFullYear() - value.getFullYear();         // set year in selected date to current year         value.setFullYear(value.getFullYear() + years);         // if the selected date is then in the future, subtract 1 from years, because the last year is not yet completed         if (value > now) {             years--;         }         check = years >= minage;         return check;     } }