+ var forbidden = test_val.match(/[^\s\d\(\)\-\+\*\/\.]/g);
+ if (forbidden && forbidden.length > 0 ){
+ return show_alert_and_focus(input_name, wrongNumberFormat);
+ }
+
+ try{
+ eval(test_val);
+ }catch(err){
+ return show_alert_and_focus(input_name, wrongNumberFormat);
+ }
+