coordinate.js

Did you ever wish you could address HTML table cells by X and Y coordinates?

<script src="coordinate.js"></script>
<script>

    var table = document.getElementsByTagName('table')[0];
    coordinate(table);

    // The origin (0,0) is the top, leftmost cell
    table.coordinates[3][2].innerHTML = '(3,2)';

</script>

Did you ever wish you could, given a table cell, easily address its neighbors?

<script src="coordinate.js"></script>
<script>

    var table = document.getElementsByTagName('table')[0];
    coordinate(table);

    var cell = table.coordinates[3][2];

    /* "edge" cells have 1 undefined direction
       corner cells have 2 undefined directions
       a cell in a 1x1 table would have all 4 directions undefined
       (but why would you do that?) */

    if (cell.north) cell.north.innerHTML = 'up';
    if (cell.south) cell.south.innerHTML = 'down';
    if (cell.west)  cell.west.innerHTML  = 'left';
    if (cell.east)  cell.east.innerHTML  = 'right';

</script>

Did you wish you could, given a table cell, know its X and Y coordinates?

<script src="coordinate.js"></script>
<script>

    var table = document.getElementsByTagName('table')[0];
    coordinate(table);

    var cells = table.getElementsByTagName('td');

    for (var i=0,td; td=cells[i]; ++i)
        td.onclick = function () {
            console.log('You just clicked on the cell at ' + this.x + ',' + this.y);
        };

</script>

I've barely tested this thing (though I did test it against table cells with colspans), and only on browsers that rhyme with "buyer stocks bee shot live". Enjoy.