if (document.images)
{
aboutnav = new Image;
aboutnav_roll = new Image;
centrifugesnav = new Image;
centrifugesnav_roll = new Image;
automationnav = new Image;
automationnav_roll = new Image;
serologynav = new Image;
serologynav_roll = new Image;
immunologynav = new Image;
immunologynav_roll = new Image;
chemistrynav = new Image;
chemistrynav_roll = new Image;
servicenav = new Image;
servicenav_roll = new Image;

aboutnav.src = "image/nav/about.gif";
aboutnav_roll.src = "image/nav/about_roll.gif";
centrifugesnav.src = "image/nav/centrifuges.gif";
centrifugesnav_roll.src = "image/nav/centrifuges_roll.gif";
automationnav.src = "image/nav/automation.gif";
automationnav_roll.src = "image/nav/automation_roll.gif";
serologynav.src = "image/nav/serology.gif";
serologynav_roll.src = "image/nav/serology_roll.gif";
immunologynav.src = "image/nav/immunology.gif";
immunologynav_roll.src = "image/nav/immunology_roll.gif";
chemistrynav.src = "image/nav/chemistry.gif";
chemistrynav_roll.src = "image/nav/chemistry_roll.gif";
servicenav.src = "image/nav/service.gif";
servicenav_roll.src = "image/nav/service_roll.gif";
}