if (document.images) {    
        
        
       	    img1on = new Image();
            img1on.src = "images/aboutRO.gif";    					  
            img2on = new Image();
            img2on.src = "images/coursesRO.gif";
            img3on = new Image();
            img3on.src = "images/registrationRO.gif";
            img4on = new Image();
            img4on.src = "images/contactRO.gif";
            img5on = new Image();
            img5on.src = "images/homeRO.gif";
           
           
            img1off = new Image(); 								
            img1off.src = "images/about.gif";
            img2off = new Image(); 								
            img2off.src = "images/courses.gif";
            img3off = new Image();
            img3off.src = "images/registration.gif";
            img4off = new Image();
            img4off.src = "images/contact.gif";
            img5off = new Image();
            img5off.src = "images/home.gif";
        
            
			}

function imgOn(imgName) {
        if (document.images) {
            document[imgName].src = eval(imgName + "on.src");
        }
}

function imgOff(imgName) {
        if (document.images) {
            document[imgName].src = eval(imgName + "off.src");
        }
}


 function openWindow(url) { 
        popupWin = window.open(url,'POP', 'width=610,height=560,scrollbars=AUTO,toolbar=0,location=0,status=0,menubar=0,resizable=1');

        popupWin.focus()
}