var forbidden = test_val.match(/[^-\+\/\*\.0-9\ ]/g );
if (forbidden && forbidden.length > 0 ){
return show_alert_and_focus(input_name, wrongNumberFormat);
var forbidden = test_val.match(/[^-\+\/\*\.0-9\ ]/g );
if (forbidden && forbidden.length > 0 ){
return show_alert_and_focus(input_name, wrongNumberFormat);