Why is rfd_total > max_rfd true? I don't understand how rfd_total can be greater than max_rfd in the following code:

max_rfd = parseFloat(jQuery('#mx-rfd_'+order_id).val()).toFixed(2);

rfd_total = parseFloat(items_total+tax_total+shipping+allowances*1).toFixed(2);


if( rfd_total > max_rfd)
{   if(isNaN(rfd_total)) alert('rfd_total isNaN'); // not triggered
    if(isNaN(max_rfd)) alert('max_rfd isNaN'); // not triggered
    alert(rfd_total); // alerts 51.16
    alert(max_rfd); // alerts 102.32
    return false;
}

• javascript
• comparison
• numeric

It's because rfd_total an max_rfd are Strings.

You will notice that "51.16" > "102.32" returns true.

toFixed() returns a string.

You will need to coerce your variables to numbers, which you can find out how to do with a quick search.

Or you can keep your code clean and do it properly using a function such as this one

function decimalRoundTo(n, decimalPlaces) {
    var d = Math.pow(10, decimalPlaces);
    return Math.round(n*d)/d;
}