I see so much different codes, but none are right for me. I made the code what I need but here is only one mistake.
IF id="numberthree" not empty, then id="result" is readonly > like: $("#result").attr("readonly","");
IF id="numberthree" is empty (clear) then can add text in id="result"
<input type="text" name="value1" id="numberone">
<input type="text" name="value2" id="numbertwo">
<input type="text" name="value3" id="numberthree">
<input type="text" name="result" id="result">
$('#numberthree').keyup(function(){
var numberone;
var numbertwo;
var numberthree;
one = parseFloat($('#numberone').val());
two = parseFloat($('#numbertwo').val());
three = parseFloat($('#numberthree').val());
var result = one + two + three;
$('#result').val(isNaN(result) ? "" : result);
});
If can help, then big thanks
