iArray=new Array(
	"http://www.duurzamevacaturebank.nl/_images/stagebank/random/rightHeader",
	"http://www.duurzamevacaturebank.nl/_images/stagebank/random/rightHeader2"
);

ri    = Math.floor(iArray.length*Math.random());
ri    ='<img src="'+ iArray[ri]+ '.jpg" border="0" alt="">';