var currMapSel = 'start';

setMenuItem = function(elt,value) {
   document.getElementById(elt).style.backgroundPosition = value;
}

setSubMenuItem = function(elt,value) {
   var obj = document.getElementById(elt).style;
   obj.backgroundImage = 'url(images/' + value + ')';
   obj.color = '#000';
}

showMapText = function(elt,value) {
   if (currMapSel != 'start') {document.getElementById(currMapSel).style.backgroundPosition = '0 0';}
   document.getElementById(currMapSel+'_txt').style.display = 'none';

   currMapSel = elt;

   document.getElementById(currMapSel).style.backgroundPosition = '0 -45px';
   document.getElementById(currMapSel+'_txt').style.display = 'block';
}