//
function randomPick()
{

var seed_num=Math.floor(Math.random()*10);
if (seed_num % 3 == 0) {
window.document.bob.src="provost_img/img_main01.jpg";
} else if (seed_num % 3 == 1) {
window.document.bob.src="provost_img/img_main02.jpg";
} else if (seed_num % 3 == 2) {
window.document.bob.src="provost_img/img_main03.jpg";
} 
}