var imgSrcs = new Array(2) 
imgSrcs[0]="http://flight.tamu.edu/images/cornerimages/1.jpg"; 
imgSrcs[1]="http://flight.tamu.edu/images/cornerimages/2.jpg";
imgSrcs[2]="http://flight.tamu.edu/images/cornerimages/3.jpg";
imgSrcs[3]="http://flight.tamu.edu/images/cornerimages/4.jpg";
imgSrcs[4]="http://flight.tamu.edu/images/cornerimages/5.jpg";
imgSrcs[5]="http://flight.tamu.edu/images/cornerimages/6.jpg";
imgSrcs[6]="http://flight.tamu.edu/images/cornerimages/7.jpg";
imgSrcs[7]="http://flight.tamu.edu/images/cornerimages/8.jpg";
imgSrcs[8]="http://flight.tamu.edu/images/cornerimages/9.jpg";
imgSrcs[9]="http://flight.tamu.edu/images/cornerimages/10.jpg";
imgSrcs[10]="http://flight.tamu.edu/images/cornerimages/11.jpg";
imgSrcs[11]="http://flight.tamu.edu/images/cornerimages/12.jpg";
imgSrcs[12]="http://flight.tamu.edu/images/cornerimages/13.jpg";

function pick_random_image() 
{ 
var bgimage=imgSrcs[(Math.round(Math.random()*(imgSrcs.length-1)))]
document.getElementById("sidebarimg").src = bgimage; 
} 
 pick_random_image();