random methog/math object

[verero]

how can i use the random method for a range of numbers not starting at zero? like: 10<=n<=20, or -3<=n<=11.

is this the right/only way (for example one)?

<script type="text/javascript">
noUnrounded=Math.random()*10;
noRounded=Math.round(noUnrounded+10);
document.writeln(noRounded);
</script>

Thanks, appreciate it.

[Jeff Mott]

/*
 * rand()      0 <= n < 1
 * rand(10)    0 <= n < 10
 * rand(4,10)  4 <= n < 10
 */
function rand()
{
    var lower = 0;
    var upper = 1;
    
    if (arguments.length == 1)
        upper = arguments[0];
    else if (arguments.length == 2) {
        lower = arguments[0];
        upper = arguments[1];
    }
    
    return Math.random() * (upper - lower) + lower;
}