var cur_letter = "A";
var letters = new Array("A","B","C","D","E","F","G","H", "I","J","K",
                        "L","M","N","O","P","Q","R","S", "T","U","V",
                        "W","Y","Z");

function display(letter){
   if(letter == "All"){
        for(i=0;i<letters.length;i++){
           var active_id = document.getElementById(letters[i]);
           active_id.style.display="";
        }
        deactivate(cur_letter);
        cur_letter = "All";
   }
   else{
       if(cur_letter=="All"){
         for(i=0;i<letters.length;i++){
             var active_id = document.getElementById(letters[i]);
             active_id.style.display="none";
         }
         deactivate("All");
       }
       else{
           var  current_id = document.getElementById(cur_letter);
           current_id.style.display="none";
           deactivate(cur_letter);
       }
       var active_id = document.getElementById(letter);
       active_id.style.display="";
       cur_letter = letter;
   }
   activate(cur_letter);
}
function activate(letter){
   var letter_id = document.getElementById('l'+letter);
   letter_id.style.backgroundColor="#8ccc1c";
   letter_id.style.color= "#ffffff";
}
function deactivate(letter){
   var letter_id = document.getElementById('l'+letter);
   letter_id.style.backgroundColor="#ffffff";
   letter_id.style.color= "#8ccc1c";
}