function MakeArray(n) 
    { 
            this.length = n; 
            for (var i = 1; i <= n; i++) 
         { 
                this[i] = 0 
         }
            return this   

    }

function Random()
   {

       Ideas=new MakeArray(7)
         numIdeas=6
    
       Ideas[0] = "header.jpg";
       Ideas[1] = "header_01.jpg"
       Ideas[2] = "header_02.jpg"
       Ideas[3] = "header_03.jpg"
       Ideas[4] = "header_04.jpg"
       Ideas[5] = "header_05.jpg"
       Ideas[6] = "header_06.jpg"

     var now= new Date()
     var sec= now.getSeconds()
        return Ideas[sec % numIdeas];
  }