export default (len:number):string =>{
    var chars = "0123456789ABCDEFGHJKLMNOPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz";
    var randomstring = '';
    for (var i=0; i<len; i++) {
        var rnum = Math.floor(Math.random() * chars.length);
        randomstring += chars.substring(rnum,rnum+1);
    }
    return randomstring;
}