var random_number="";
var image1="";
random_number = Math.round(Math.random() * 9) + 1;

if (random_number==1) {
image1="images/main1.gif";
}
if (random_number==2) {
image1="images/main2.gif";
}
if (random_number==3) {
image1="images/main3.gif";
}
if (random_number==4) {
image1="images/main4.gif";
}
if (random_number==5) {
image1="images/main5.gif";
}
if (random_number==6) {
image1="images/main6.gif";
}
if (random_number==7) {
image1="images/main7.gif";
}
if (random_number==8) {
image1="images/main8.gif";
}
if (random_number==9) {
image1="images/main9.gif";
}
if (random_number==10) {
image1="images/main10.gif";
}
document.write("<img src='"+image1+"'WIDTH=90 HEIGHT=90 hspace=0 vspace=0>");