Question

i want a jquery source to calculate my form

<form>
      <input type="radio" name="type" value="1000"> $1000
      <input type="radio" name="type" value="2000"> $2000
      <input type="radio" name="type" value="3000"> $3000
      <input type="radio" name="type" value="4000"> $4000
      <input type="radio" name="type" value="5000"> $5000

    <select name="number">
      <option name="number" value="1">1</option>
      <option name="number" value="1">2</option>
      <option name="number" value="1">3</option>
      <option name="number" value="1">4</option>
      <option name="number" value="1">5</option>
    </select>

</form>

must type*number and show total in text input

Answer 1

You can bind a change() to both the :radio and <select/> elements to calculate the total.

$("select[name='number'], :radio[name='type']").change(function(){
    var $r = $(":radio[name='type']:checked");
    var $d = $("select[name='number']");
    if($r.length ==1){
        var t = parseInt($r.val(), 10);
        var n = parseInt($d.val(), 10);
        $("#result").val(t*n);
    }
});

Example on jsfiddle