var number = 2
var zak = new Array(number+1);
var sfer = new Array(number+1);
var pic = new Array(number+1);

zak[0]="Три кита"
zak[1]="Спросить Петровича"
zak[2]="Палермо"

sfer[0]="Рекламный бизнес"
sfer[1]="Строительство"
sfer[2]="Ресторанный бизнес"

pic[0]="pic0.gif"
pic[1]="pic1.gif"
pic[2]="pic2.gif"


function randomtxt() {
var randscript = -1
while (randscript < 0 || randscript > number || isNaN(randscript)){
randscript = parseInt(Math.random()*(number+1))
}
return randscript
}

quo = randomtxt();

nzak = zak[quo];
nsfer = sfer[quo];
npic = pic[quo];

document.write('<strong>Заказчик:</strong><br />');
document.write(nzak);
document.write('<br /><strong>Сфера деятельности:</strong><br />');
document.write(nsfer);
document.write('<div><img alt="" src="banners/');
document.write(npic);
document.write('" /></div>');