function getRandom()
{
    var ranNum = Math.round(Math.random()*4);
    return ranNum;
}

function selectRandomImg()
{
	var index = getRandom();

    var images = new Array(4);
    images[0]="sb1.gif";
    images[1]="sb2.gif";
    images[2]="sb3.gif";   
    images[3]="sb4.gif";
    images[4]="sb5.gif";
  	
  	document.sidebar.src = imgPath + images[index];
}

function rotateImg()
{
	selectRandomImg();
	setTimeout("rotateImg()",30000);
}