function MM_openBrWindow(theURL,winName,features) { //v2.0
  window.open(theURL,winName,features);
}  

function obrazek(nazwa,impreza,rok,ulozenie)
{
 var width, height;
 
 if(ulozenie=='v') 
 {
  width=170; height=240;
 }
 else if(ulozenie=='h') 
 {
  width=240; height=170; 
 }
 
 document.writeln("<a href=javascript:; onClick=MM_openBrWindow('images/"+ impreza +"/"+ rok +"/"+nazwa+".jpg','walka','resizable=yes,width="+(width*3.5)+",height="+(height*3.5)+",scrollbars=yes')><img src=images/"+ impreza +"/"+ rok +"/"+nazwa+"_m.jpg width="+width+" height="+height+"></a>");
}