一段实现除去字符串中重复的js代码

function okd(){
var o = document.getElementsByName("number")[0];
var array = new Array();
var k =0;
for(var i=0;i<o.value.length;i++){
       if(array == "" || array.toString().match(new RegExp(o.value.charAt(i),"g")) == null){
           array[k] =o.value.charAt(i);
           array.sort();
           k++;
       }
}               
alert(array.toString());
}