rnd.today=new Date(); 
rnd.seed=rnd.today.getTime(); 

function rnd()
{ 
　　rnd.seed = (rnd.seed*9301+49297) % 233280; 
　　return rnd.seed/(233280.0); 
}

function rand(number)
{ 
　　return Math.ceil(rnd()*number); 
}