Array.prototype.delRepeat=function() 
  { 
        var tmpArr=[],rs=[],i,val; 
        for(i=this.length;i>0;i--) 
    { 
            val = this[i-1]; 
      if(!tmpArr[val]) 
      { 
                tmpArr[val]=1; 
            }else 
      { 
                rs.push(val); 
          this.splice(i-1,1); 
            } 
        } 
    tmpArr = null; 
        return rs; 
    }