btn1=new Image();
btn1_a=new Image();
btn1_b=new Image();
btn1.src="buttons/btn_uvod.gif";
btn1_a.src="buttons/btn_uvod_a.gif";
btn1_b.src="buttons/btn_uvod_b.gif";

btn2=new Image();
btn2_a=new Image();
btn2_b=new Image();
btn2.src="buttons/btn_ohotelu.gif";
btn2_a.src="buttons/btn_ohotelu_a.gif";
btn2_b.src="buttons/btn_ohotelu_b.gif";

btn3=new Image();
btn3_a=new Image();
btn3_b=new Image();
btn3.src="buttons/btn_ubyt.gif";
btn3_a.src="buttons/btn_ubyt_a.gif";
btn3_b.src="buttons/btn_ubyt_b.gif";

btn4=new Image();
btn4_a=new Image();
btn4_b=new Image();
btn4.src="buttons/btn_konf.gif";
btn4_a.src="buttons/btn_konf_a.gif";
btn4_b.src="buttons/btn_konf_b.gif";

btn5=new Image();
btn5_a=new Image();
btn5_b=new Image();
btn5.src="buttons/btn_strav.gif";
btn5_a.src="buttons/btn_strav_a.gif";
btn5_b.src="buttons/btn_strav_b.gif";

btn6=new Image();
btn6_a=new Image();
btn6_b=new Image();
btn6.src="buttons/btn_sluzby.gif";
btn6_a.src="buttons/btn_sluzby_a.gif";
btn6_b.src="buttons/btn_sluzby_b.gif";

btn7=new Image();
btn7_a=new Image();
btn7_b=new Image();
btn7.src="buttons/btn_okoli.gif";
btn7_a.src="buttons/btn_okoli_a.gif";
btn7_b.src="buttons/btn_okoli_b.gif";


function chg(co, jak)
{
	jak_orig=jak;
		
	btn_act=document.images[co].src;
	delka_act=btn_act.length-6;
	konc_act=btn_act.substr(delka_act,2);	
	
	jak=eval(jak+'.src');
	delka=jak_orig.length-2;
	konc=jak_orig.substr(delka,2);

	hlaska=btn_act + "\n" + delka_act + "\n" + konc_act + "\n\n"+ jak;
	//alert(hlaska);
	
	if (konc_act=="_b") 
		{ promen=0; }
	else
		{ if(konc=="_b") {clear();}
		  promen=1; 
		}

	if (promen==1)
		{ document.images[co].src=jak; }

}


function skryj(div)
{
    if (document.getElementById(div).style.display=='none')
	{
	document.getElementById(div).style.display='block';
	}
     else
	{
    document.getElementById(div).style.display='none';
	}
}