var howMany = 4
  var quote = new Array(howMany+1)
  quote[0]="<img src='img/base/random1.jpg'>"
  quote[1]="<img src='img/base/random2.jpg'>"
  quote[2]="<img src='img/base/random3.jpg'>"
  quote[3]="<img src='img/base/random4.jpg'>"
  quote[4]="<img src='img/base/random5.jpg'>"
  
function rndnumber(){
        var randscript = -1
        while (randscript < 0 || randscript > howMany || isNaN(randscript)){
                randscript = parseInt(Math.random()*(howMany+1))
        }
        return randscript
}
     quo = rndnumber()
     quox = quote[quo]
document.write(quox)