aktiv='b1';

ns4 = (document.layers)? true:false;
ns6 = (document.getElementById && !document.all)? true:false;
ie4 = (document.all)? true:false;

var DHTML = 0, DOM = 0, MS = 0, NS = 0, OP = 0;

function DHTML_init() {

 if (window.opera) {
     OP = 1;
 }
 if(document.getElementById) {
   DHTML = 1;
   DOM = 1;
 }
 if(document.all && !OP) {
   DHTML = 1;
   MS = 1;
 }
if(document.layers && !OP) {
   DHTML = 1;
   NS = 1;
 }
}

function getElem(p1,p2,p3) {
 var Elem;
 if(DOM) {
   if(p1.toLowerCase()=="id") {
     if (typeof document.getElementById(p2) == "object")
     Elem = document.getElementById(p2);
     else Elem = void(0);
     return(Elem);
   }
   else if(p1.toLowerCase()=="name") {
     if (typeof document.getElementsByName(p2) == "object")
     Elem = document.getElementsByName(p2)[p3];
     else Elem = void(0);
     return(Elem);
   }
   else if(p1.toLowerCase()=="tagname") {
     if (typeof document.getElementsByTagName(p2) == "object" ||
        (OP && typeof document.getElementsByTagName(p2) == "function"))
     Elem = document.getElementsByTagName(p2)[p3];
     else Elem = void(0);
     return(Elem);
   }
   else return void(0);
 }
 else if(MS) {
   if(p1.toLowerCase()=="id") {
     if (typeof document.all[p2] == "object")
     Elem = document.all[p2];
     else Elem = void(0);
     return(Elem);
   }
   else if(p1.toLowerCase()=="tagname") {
     if (typeof document.all.tags(p2) == "object")
     Elem = document.all.tags(p2)[p3];
     else Elem = void(0);
     return(Elem);
   }
   else if(p1.toLowerCase()=="name") {
     if (typeof document[p2] == "object")
     Elem = document[p2];
     else Elem = void(0);
     return(Elem);
   }
   else return void(0);
 }
 else if(NS) {
   if(p1.toLowerCase()=="id" || p1.toLowerCase()=="name") {
   if (typeof document[p2] == "object")
     Elem = document[p2];
     else Elem = void(0);
     return(Elem);
   }
   else if(p1.toLowerCase()=="index") {
    if (typeof document.layers[p2] == "object")
     Elem = document.layers[p2];
    else Elem = void(0);
     return(Elem);
   }
   else return void(0);
 }
}

DHTML_init();



function preload(imgObj,imgSrc) {
	if (document.images) {
		eval(imgObj+' = new Image()')
		eval(imgObj+'.src = "t/img/t_'+imgSrc+'.gif"')

		eval(imgObj+'on = new Image()')
		eval(imgObj+'on.src = "t/img/t__'+imgSrc+'.gif"')

		eval(imgObj+'aktiv = new Image()')
		eval(imgObj+'aktiv.src = "t/img/t___'+imgSrc+'.gif"')
	}
}



preload('b1' ,'03');
preload('b2' ,'04');
preload('b3' ,'05');
preload('b4' ,'06');
preload('b5' ,'07');
preload('b6' ,'08');


function tab_on(name) {

	tab_off ('b1' );
	tab_off ('b2' );
	tab_off ('b3' );
	tab_off ('b4' );
	tab_off ('b5' );
	tab_off ('b6' );
	
	c = getElem("id", "tab_" + name ,0);
    
   	if (ns4) {document.layers['tab_'+name].visibility = "show";}
	if (ie4) {c.style.visibility = "visible";}
	if (ns6) {c.style.visibility = "visible";}
}


function tab_off(name) {
 
	c = getElem("id", "tab_" + name ,0);

	if (ns4) {document.layers['tab_'+name].visibility = "hide";}
	if (ie4) {c.style.visibility = "hidden";}
	if (ns6) {c.style.visibility = "hidden";}
}



function clk(name){

	aktiv1= aktiv;
	aktiv = name;

	off (aktiv1);
	
	on  (aktiv);
	
	tab_on ( name );

	c = getElem("name",name ,0);

	if (ns4){document.Nr.document.images[name].src=eval(name+"aktiv.src");}
	if (ie4){c.src=eval(name+"aktiv.src");}
	if (ns6){c.src=eval(name+"aktiv.src");}
}

function on(name){

	if (aktiv==name)
	        {}
	   else {

	c = getElem("name",name ,0);

	if (ns4){document.Nr.document.images[name].src=eval(name+"on.src");}
	if (ie4){c.src=eval(name+"on.src");}
	if (ns6){c.src=eval(name+"on.src");}
}}


function off(name){

	if (aktiv==name)
	        {}
	   else {
	
	c = getElem("name",name ,0);
	
	if (ns4){document.Nr.document.images[name].src=eval(name+".src");}
	if (ie4){c.src=eval(name+".src");}
	if (ns6){c.src=eval(name+".src");}
}}