function RondomPass(number){

    var arr = new Array;

    var arr1 = new Array("","","","","","","","","","");

    for(var i=;i<number;i++){

        var n = Math.floor(Math.random()*);

        arr[i] =arr1[n] ;

        //document.write(arr1[n]);

    }

    val = arr.join("")

    //document.write(val);

    return val;    

}

RondomPass（）