Multiple id's in a single JavaScript click event

Try this:

var that = this;
$('#pro1,#pro2,#pro3').click(function () {
    chart.series[0].update({
        data: that[$(this).attr('id')];
    });
});

I would suggest creating an object and selecting the elements using classes, id of the clicked element retrieves value of the corresponding property of the helper object:

var pros = {
   pro1: '...',
   pro2: '...'
};

$('.pros').click(function () {
    chart.series[0].update({
        data: pros[this.id]
    });
});

$('#pro1,#pro2,#pro3').click(function () {
    chart.series[0].update({
        data: $(this).attr('id');
    });
});

Updated code

$('#pro1,#pro2,#pro3').click(function () {
    chart.series[0].update({
        data: window[this.id]
    });
});