var x = 10;
while (x --> 0) // x goes to 0
{
   document.writeln(x);
}

var x = 0;
while (x ++< 10) // x goes to 10
{ document.writeln(x); }

the other direction, in case you wondered... neety shortcut, though i like groovy ranges better ( groovy.codehaus.org )

the other direction is not so easy to fall for – thus, less groovy, anyway :)