Cleaning Windows

So in our new apartment we live on the 13 floor and we have been wondering how to clean the windows.  Today Little N shouted at John saying, "Hey dad look at the guy on the ledge." We were shocked when we looked outside and saw two people on the ledge cleaning on the window. We will not be cleaning our windows that way....we'll try to find a long window wiper to clean our windows.  We also had to tell both Little N and Little M that they were not allowed to climb out of the windows. Thankfully we have child safety locks on all the windows.