What's the proper way of using Javascript's window.opener?

I've created a popup window and in it I'd like to use a function I've created in the parent window. I've tried using window.opener.parentFunction() but to know avail. Has anyone else experienced this problem? Here's what my code looks like.

function parentFunction(){
alert('testing');
}


function print(){
var new_win = window.open('','name','height=400,width=500');
var output = "<html><head></head><body><table>\n";


for (i = 0; i < 10; i++) {
output += "<td onclick='window.opener.parentFunction()'>"+i+"</td>";
}

output += "</table></body></html>\n";
new_win.document.write(output);
}

*Got it working. Thanks guys.

Solution

There are a bunch of problems with your code. I've put together a working demo here.

HTML

<button id="clickMe">Click me</button>

JavaScript

window.onload = function() {

    function parentFunction() {
        alert('testing');
    }

    window.parentFunction = parentFunction;

    var years = [1, 2, 3, 4, 5, 6];

    function print() {
        var new_win = window.open('', 'name', 'height=400,width=500');
        //var cols = this.getCols();
        var cols = 2;
        var output = "<html><head></head><body><table>";
        var cell_count = 1;
        for (i = 0; i < years.length; i++) {
            if (cell_count === 1) {
                output += "<tr>";
            }
            output += "<td onclick='window.opener.parentFunction();'>" + years[i] + "</td>";
            cell_count++;
            // end the row if we've generated the expected number of columns
            // or if we're at the end of the array
            if (cell_count > cols || i === years.length - 1) {
                output += "</tr>\n";
                cell_count = 1;
            }
        }
        output += "</table></body></html>";
        new_win.document.write(output);
    }

    document.getElementById('clickMe').onclick = print;
};

years was not defined
this.getCols() was not defined
parentFunction was (probably) not visible at the window scope