/*
 * From: http://www.openjs.com/scripts/events/keyboard_shortcuts/
 * Enhanced by: Foteos Macrides
 */
function shortcut(shortcut,callback,opt){
 // Provide a set of default options
 var default_options={'type':'keydown','propagate':false,'target':document}
 if(!opt)opt=default_options;
 else{for(var dfo in default_options){if(typeof opt[dfo]=='undefined')opt[dfo]=default_options[dfo];}}
 var ele=opt.target
 if(typeof opt.target=='string')ele=document.getElementById(opt.target);
 var ths=this;
 // The function to be called at keypress
 var func=function(e){
  e=(e||window.event);
  // Find Which key is pressed
  if(e.keyCode)code=e.keyCode;
  else if(e.which)code=e.which;
  var character=String.fromCharCode(code).toLowerCase();
  var keys=shortcut.toLowerCase().split("+");
  // Key Pressed - counts number of valid keypresses - if same as the number of keys, shortcut function is invoked
  var kp = 0;	
  // Work around for stupid Shift key bug created by using lowercase - as a result the shift+num combination was broken
  var shift_nums={
   "`":"~",
   "1":"!",
   "2":"@",
   "3":"#",
   "4":"$",
   "5":"%",
   "6":"^",
   "7":"&",
   "8":"*",
   "9":"(",
   "0":")",
   "-":"_",
   "=":"+",
   ";":":",
   "'":"\"",
   ",":"<",
   ".":">",
   "/":"?",
   "\\":"|"
  }
  // Special Keys - and their codes
  var special_keys={
   'esc':27,
   'escape':27,
   'tab':9,
   'space':32,
   'return':13,
   'enter':13,
   'backspace':8,
   
   'scrolllock':145,
   'scroll_lock':145,
   'scroll':145,
   'capslock':20,
   'caps_lock':20,
   'caps':20,
   'numlock':144,
   'num_lock':144,
   'num':144,
   
   'pause':19,
   'break':19,
   
   'insert':45,
   'home':36,
   'delete':46,
   'end':35,
   
   'pageup':33,
   'page_up':33,
   'pu':33,
   
   'pagedown':34,
   'page_down':34,
   'pd':34,
   
   'left':37,
   'up':38,
   'right':39,
   'down':40,
   
   'f1':112,
   'f2':113,
   'f3':114,
   'f4':115,
   'f5':116,
   'f6':117,
   'f7':118,
   'f8':119,
   'f9':120,
   'f10':121,
   'f11':122,
   'f12':123
  }
  for(var i=0;k=keys[i],i<keys.length;i++){
   // Modifiers
   if(k=='ctrl'||k=='control'){
    if(e.ctrlKey)kp++;
   }else if(k=='shift'){
    if(e.shiftKey)kp++;
   }else if(k=='alt'){
    if(e.altKey)kp++;
   }else if(k=='meta'||k=='cmd'||k=='command'||k=='apple'){
    if(e.metaKey)kp++;
   }else if(k.length>1){// If it is a special key
    if(special_keys[k]==code)kp++;
   }else{// The special keys did not match
    if(character==k)kp++;else{
     if(shift_nums[character]&&e.shiftKey){// Stupid Shift key bug created by using lowercase
      character=shift_nums[character]; 
      if(character==k)kp++;
     }
    }
   }
  }
  if(kp==keys.length){
   callback(e);
   if(!opt['propagate']){// Stop the event
    // e.stopPropagation works in Firefox, Safari
    if (e.stopPropagation){e.stopPropagation();e.preventDefault();}
    // e.cancelBubble works in IE
    else if (typeof e.cancelBubble=='boolean'){e.keyCode=0;e.cancelBubble=true;e.returnValue=false;}
    return false;
   }
  }
 }
 // Attach the function with the event
 if(ele.addEventListener){ele.addEventListener(opt['type'],func,false);
  if(opt['type']=='keydown')ele.addEventListener('keypress',func,false);}
 else if(ele.attachEvent){ele.attachEvent('on'+opt['type'],func);
  if(opt['type']=='keydown')ele.attachEvent('onkeypress',func);}
 else{ele['on'+opt['type']]=func;if(opt['type']=='keydown')ele['onkeypress']=func;}
}