//preload images

img2on  = new Image();  img2on.src  = "assets/images/menu/navibut_home.gif";
img2off = new Image();  img2off.src = "assets/images/menu/navibut_home_on.gif";
img3on  = new Image();  img3on.src  = "assets/images/menu/navibut_info.gif";
img3off = new Image();  img3off.src = "assets/images/menu/navibut_info_on.gif";
img4on  = new Image();  img4on.src  = "assets/images/menu/navibut_bjunl.gif";
img4off = new Image();  img4off.src = "assets/images/menu/navibut_bjunl_on.gif";
img5on  = new Image();  img5on.src  = "assets/images/menu/navibut_search.gif";
img5off = new Image();  img5off.src = "assets/images/menu/navibut_search_on.gif";
img6on  = new Image();  img6on.src  = "assets/images/menu/navibut_subscription.gif";
img6off = new Image();  img6off.src = "assets/images/menu/navibut_subscription_on.gif";
img7on  = new Image();  img7on.src  = "assets/images/menu/navibut_abonnementen.gif";
img7off = new Image();  img7off.src = "assets/images/menu/navibut_abonnementen_on.gif";
img8on  = new Image();  img8on.src  = "assets/images/menu/navibut_statistics.gif";
img8off = new Image();  img8off.src = "assets/images/menu/navibut_statistics_on.gif";
img9on  = new Image();  img9on.src  = "assets/images/menu/navibut_periodieken.gif";
img9off = new Image();  img9off.src = "assets/images/menu/navibut_periodieken_on.gif";


function imgon(imgName) {
	if (document.getElementById)		{
		trp=document.getElementById(imgName);
		trp.src = eval(imgName + "off.src");
		}
    }

function imgoff(imgName) {
	if (document.getElementById)		{
		trp=document.getElementById(imgName);
		trp.src = eval(imgName + "on.src");        
		}
    }

function clearform()	{
	 document.searchform.search_terms.value="";
	 document.searchform.search_authors.value="";
	 document.searchform.search_title.value="";
 }