<!-- 
function overwrite(thefield){if (thefield.defaultValue==thefield.value)thefield.value = ""}
function roundit(Num,digits) {if (digits > 0) {if ((Num.toString().length - Num.toString().lastIndexOf('.')) > (digits + 1)) {var Rounder = Math.pow(10,digits); return Math.round(Num * Rounder) / Rounder; } else return Num;} else return Math.round(Num);}
function convert(form){form.hertz.value = "cm. "+roundit((34359/form.hertz.value),2)}
// -->