Question

I have an expense report type form that has an input asking for mileage. When a user types in a number, I’d like there to be an auto calculate sort of function that displays the amount they will be reimbursed.

For instance, if a user types in “65”, to the right of the input box would be “65 x $.555 = $36.08”.

JS is not my strong suit, but I know I’ll need to use a hidden div to display the JS generated text, and some code to make sure the “total” is rounded to 2 decimal places. Any ideas/suggestions?

Answer 1

Example

$(function () {
    $('#amount').change(function () {
         var $this = $(this);

        $this.next('label').text((parseFloat($this.val()) * .555).toFixed(2))            
    });        
});​

jQuery isn’t needed, but helpful.

toFixed method

parseFloat method

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If you needed to do the rounding:

var rounded = Math.round(parseFloat($this.val()) * 100) / 100;