/*
JavaScript Bible, Fourth Edition
by Danny Goodman
John Wiley & Sons CopyRight 2001
*/
Got a Match?
function commafy(form) {
var re = /(-?\d+)(\d{3})/
var num = form.entry.value
while (re.test(num)) {
num = num.replace(re, "$1,$2")
}
form.commaOutput.value = num
}
function decommafy(form) {
var re = /,/g
form.plainOutput.value = form.commaOutput.value.replace(re,"")
}
Use a regular expression to add/delete commas from numbers: