var rands=new Array()

//change the rands if desired. Add/ delete additional rands as desired.

rands[0]='<img src="images/rand1.jpg" alt="cogent partners, legionella brisbane" />'

rands[1]='<img src="images/rand2.jpg" alt="cogent partners, legionella brisbane" />'

rands[2]='<img src="images/rand3.jpg" alt="cogent partners, legionella brisbane" />'

rands[3]='<img src="images/rand4.jpg" alt="cogent partners, legionella brisbane" />'


var whichrand=Math.floor(Math.random()*(rands.length))
document.write(rands[whichrand])