JS referenceError: change is not defined

Question

I have 4 input boxes that call a function when the key is lifted using the onkeyup event. For some reason, I am getting an error saying that "change" (the function's name) is not defined. I am definitely defining the function correctly, so I have no idea what's causing this.

The demo will explain much better than me:
_{(source: snag.gy)}

OK, got it. I was getting that error, but the cause what not what I had suspected. http://jsfiddle.net/qWcZ6/2/

Answer 1

Not sure what exactly you're trying to do, but the following works (fiddle):

function change(variable) {
    var value = $(variable).val();
    alert(value);
    $(variable).html(value);
}

Answer 2

This is a better pattern.

<mtext><input id="y" value="y" class="vars"></input></mtext>
<mo>=</mo>
<mtext><input id="m" value="m" class="vars"></input></mtext>
<mo>&#x00D7;</mo>
<mtext><input id="x" value="x" class="vars"></input></mtext>
<mo>+</mo>
<mtext><input id="b" value="b" class="vars"></input></mtext>

    $(document).ready(function(){
        function change() {
            var value = $(this).val();
            //alert(value);
            if (console && typeof console.log !== 'undefined') {
                console.log("value",value);
            }
        }
        $('.vars').on('keyup',change);
    });

http://jsfiddle.net/BELIKEMIKE/WAcLW/2/