Javascript to format number as currency -

i have following code.

<select id="cage_options">    <option>please select</option>    <option value="2,63330">option1</option>    <option value="3,13300">option2</option>    <option value="4,2000.00">option3</option> </select> <input id="cage_labor_estimate" disabled>  <script>    function format(n) {        return n.tofixed(2).replace(/(\d)(?=(\d{3})+\.)/g, "$1,");    }     document.getelementbyid("cage_options").addeventlistener("change", cageoptionfunction);     function cageoptionfunction() {         select=document.getelementbyid('cage_options').value.split(',');         cage_option = select[1];         document.getelementbyid("cage_labor_estimate").value = format(cage_option);    }  </script> 

i trying format output in disabled input box in current format following error:

typeerror: n.tofixed not function. (in 'n.tofixed(2)', 'n.tofixed' undefined)

can help?

thanks,

john

you have string , string not have .tofixed(). need convert string number.

cage_option = number(select[1]); 

or

cage_option = parsefloat(select[1]);