Array.prototype.distinct　= function () {

var thix = this,

_a = this.concat().sort(),

n = 0;

_a.sort(function (a, b) {

if(a === b) {

n = thix.indexOf(a);

thix.splice(n,1);

}

});

return thix;

};

var arr = new Array(1,20,3,4,5,6,70,8,1,2,8);

arr.distinct();