var howMany = 5
var logo = new Array(howMany+1)
logo[0]="card01"
logo[1]="card02"
logo[2]="card03"
logo[3]="card04"
logo[4]="card05"

logox = logo[Math.ceil(Math.random()*howMany+1)-2]
document.write("<img src='gallery/"+logox+".jpg' ALT='Purzotics Cattery' class='floatright'>")