var ar= new Array('aa','bb','cc');
alert(ar);
function selAr(){
var tmp = Math.round(Math.random(ar.length)*ar.length)-1;
var re = ar[tmp];
var tmpar = new Array();
for (var i=0;i<ar.length;i++){
if (i != tmp){
tmpar[tmpar.length]=ar[i];
}
}
ar=tmpar;
return re;
}