var matching = new RegExp(dateFormat.replace(/\w/g, '\\d') + "\$","ig");
if(!(dateFormat.lastIndexOf("y") == 3) && !matching.test(input_name.value)) {
matching = new RegExp(dateFormat.replace(/\w/g, '\\d') + '\\d\\d\$', "ig");
var matching = new RegExp(dateFormat.replace(/\w/g, '\\d') + "\$","ig");
if(!(dateFormat.lastIndexOf("y") == 3) && !matching.test(input_name.value)) {
matching = new RegExp(dateFormat.replace(/\w/g, '\\d') + '\\d\\d\$', "ig");