  I am going to be posting a series of useful JavaScript functions for form validation and input formatting. This is the first in that series: a function which formats a number as currency. function formatCurrency(num) { num = num.toString().replace(/\$|\,/g,''); if(isNaN(num)) num = "0"; sign = (num == (num = Math.abs(num))); num = Math.floor(num*100+0.50000000001); cents = num%100; num = Math.floor(num/100).toString(); if(cents return (((sign)? '':'-') + num + '. ' + cents); } 
