Calendar.setup(
            {
            inputField : "anreise", // ID of the input field
            ifFormat : "%d.%m.%y", // the date format
            button : "cal_arr" // ID of the button
            }
            );

            Calendar.setup(
            {
            inputField : "abreise", // ID of the input field
            ifFormat : "%d.%m.%y", // the date format
            button : "cal_dep" // ID of the button
            }
            );