Mnożenie v3

<style>
#x, #y{
    text-align: center;
    color: white;
    background-color: black;
    font-weight: bolder;
    float: left;
    width: 30px;
}

#z{
    text-align: center;
    color: black;
    float: left;
    width: 30px;
}
</style>

<script type="text/javascript">


var $y=prompt(('Podaj zakres Y: '));
var $x=prompt(('Podaj zakres X: '));
$z=$y;

    for (var y=0; y<=$y; y++){
            document.write('<span id="y">'+y+' </span>');
        }
    for (var x=1; x<=$x; x++){
            document.write ('<br><span id="x">'+x+'</span>');
            for (z=1;z<=$z; z++){
                document.write('<span id="z">'+z*x+'</span>');
            }
        }
</script>