// JavaScript Document
var n = 20;
var f = false;
var b = new Array;
var v = new Array;
var st = 0;
function prel(){

   	if(document.images) {
	  for(i=1;i<=n;i++)
               {str = 'buttons/b' + i + '_o.gif';
			   str1 = 'buttons/b' + i + '_v.gif';
               b[i-1] = new Image();
               b[i-1].src = str;
			   v[i-1] = new Image();
			   v[i-1].src = str1;
}f = true;
 		}
}
function on(im){
	if (document.images && (f == true) && !st) 
		{document.images[im].src="buttons/"+im+"_o.gif";}
		
}
function off(im){
	if (document.images && (f == true) && !st)
		{document.images[im].src = "buttons/"+im+".gif";}
}
 function show(im, block)
 {
	if(document.images && (f == true))	
	{if(!st){
		document.images[im].src = "buttons/"+im+"_v.gif";
		document.getElementById(block).style.display = "block";		
		st=1;
	}else{document.images[im].src = "buttons/"+im+".gif";
		document.getElementById(block).style.display = "none";		
		st=0;}
		//!st?st=1:st=0;		
	}
}