var hist=new Array();
 var i=0;  hist[0]='';
 var loc='';
 var j=0;
 var msie=-1;
 var topp='#topp';


 if (document.all) {msie=1;}  


function hist_init() {
   if (location.hash) { hist[0]=location.hash; } else { hist[0]=topp; }
   loc=hist[0]; 
   histor();
}


function histor() {
     if (location.hash) { loc=location.hash; }  else { loc=topp; }
     if  (loc==hist[j]) { setTimeout('histor()', 500); }
        else { i=i+1; j=i;  hist[i]=loc;  setTimeout('histor()', 500); } 
}


function backward() {
  if (j>=1) { 
         j=j-1;  
         if (msie==-1) { location.replace(hist[j]); }  
            else { location.hash=hist[j];  history.back(); }
   }
  return false;
}


function forward() {
  if (j<=i-1) { 
         j=j+1;  
         if (msie==-1) { location.replace(hist[j]); }  
            else { location.hash=hist[j];  history.back();  }
   }
  return false;
}