1var regex = new RegExp("^[A-Za-z0-9? ,_-]+$");
2            var key = String.fromCharCode(event.charCode ? event.which : event.charCode);
3            if (!regex.test(key)) {
4                event.preventDefault();
5                return false;
6            }
71def isAlphaNumericStr(text):
2   if(re.match("^[A-Za-z0-9 -]+$", text) != None):
3     return True
4
5   root.bell()
6   return False
7 
8 #TO ACTIVATE ON FIELD
9 txtCustomerName.configure(validate="key", validatecommand = (txtCustomerName.register(isAlphaNumericStr),'%P'))