/*
Copyright (c) 2004 Ylab, http://www.ylab.nl
*/

//trap error
/*
window.onerror = function(msg, url, line){
  window.status = "Er is een fout opgetreden. Meld dit a.u.b. aan de webmaster. " + line + ": " + msg;
  return true;
};*/

var debugging = false;
var isOpera = (navigator.userAgent.indexOf("Opera") > -1);
var isNav = ((!isOpera) && (navigator.appName == "Netscape"));
var isIE  = ((!isOpera) && (navigator.appName.indexOf("Explorer") > -1 ));

var loadFunctions = [];
function addLoadFunction(f)  {loadFunctions[loadFunctions.length] = new Function(f);}
window.onload   = function() {for (var i=0; i<loadFunctions.length; i++){loadFunctions[i]();}};

//display mailto link
function printMail(username, linktext){
  username = username.toLowerCase() + "@centrumutrecht.nl";
  if (!linktext) {linktext = username;}
  document.write(linktext.link("mailto:" + username));
}

//Convert id into object
function id2object(el){
  if (typeof(el)=="string"){el = document.getElementById(el);}
  return el;
}

function callMethodsForEvent(obj, handler){
  if (!obj.methods || !obj.methods[handler]){return;}
  for (var i=0; i<obj.methods[handler].length; i++){obj.methods[handler][i].call(obj);}
}

function addEvent(obj, handler, f){
  if (!obj){return;}
  //prepare method storage
  if (!obj.methods){obj.methods = [];}
  if (!obj.methods[handler]){obj.methods[handler] = [];}
  //the generic method wich will call the actual methods
  var parentMethod = function(){callMethodsForEvent(this, handler);};
  if (!obj[handler]){
    obj[handler] = parentMethod;
  }
  else if (obj[handler].toString() != parentMethod.toString()){
    //store existing method
    obj.methods[handler].push(obj[handler]);
    obj[handler] = parentMethod;
  }
  //store new method
  if (typeof(f) != "function"){f = new Function(f);}
  obj.methods[handler].push(f);
}

//Set focus on first input element
function setFirstFieldFocus(container){
	var list;
  if(container.tagName == "FORM"){
    list = container.elements;
  }
  else{
    list = container.getElementsByTagName("input");
  }
  for (var i=0; i< list.length; i++){
    try {
      if (list[i].type == "button"){continue;}
      list[i].focus();
      if(list[i].select){list[i].select();}
      break;
    }
    catch (exception){}
  }
}

//enable or disable elements and their children
function setEnabled(on){
  for (var i=1; i<arguments.length; i++){
    var obj = id2object(arguments[i]);
    if (!obj){continue;}
    obj.disabled = !on;
    if(on){
    	removeClass(obj, 'disabled');
    }
    else{
    	addClass(obj, 'disabled');
    }
    if (obj.hasChildNodes()){
      for (var j=0; j<obj.childNodes.length; j++){
        if (obj.childNodes[j].nodeType == 1){setEnabled(on, obj.childNodes[j]);}
      }
    }
  }
}

function addClass(obj, strClass){
	if(!obj){return;}
	if(!obj.className){
		obj.className = strClass;
	}
	else if(!obj.className.match(strClass)){
		obj.className += ' ' + strClass;
	}
}

function removeClass(obj, strClass){
	if(!obj || !obj.className){return;}
	 obj.className = obj.className.replace(strClass, '');
}

//set a style property or fail gracefully
function setStyle(objectId, prop, value){
  var obj = document.getElementById(objectId);
  if ((obj) && (obj.style[prop] != value)){
    obj.style[prop] = value;
  }
}

function Viewport(){
  this.x = 0;
  this.y = 0;
  if (self.innerHeight) {
    // all except Explorer
  	this.x = self.innerWidth;
  	this.y = self.innerHeight;
  }
  else if (document.documentElement && document.documentElement.clientHeight){
    // Explorer 6 Strict Mode
  	this.x = document.documentElement.clientWidth;
  	this.y = document.documentElement.clientHeight;
  }
  else if (document.body){
    // other Explorers
  	this.x = document.body.clientWidth;
  	this.y = document.body.clientHeight;
  }
}


//COOKIES
function getCookie(name){
  //Function to return the value of the cookie specified by "name".
  //returns: String object containing the cookie value, or null if the cookie does not exist.

  var arg = name + "=";
  var alen = arg.length;
  var clen = document.cookie.length;
  var i = 0;
  var j = 0;

  function getCookieVal(offset){
  	//Internal function to return the decoded value of a cookie
    var endstr = document.cookie.indexOf (";", offset);

    if (endstr == -1){
    	endstr = document.cookie.length;
    }
    return unescape(document.cookie.substring(offset, endstr));
  }

  while (i < clen) {
    j = i + alen;
    if (document.cookie.substring(i, j) == arg){
      return getCookieVal (j);
    }
    i = document.cookie.indexOf(" ", i) + 1;
    if (i === 0){
    	break;
    }
  }
  return null;
}

function setCookie(name, value){
  //Function to create or update a cookie for calling document.
  document.cookie = name + "=" + escape (value);
}

//DEBUGGING
function devAlert(){
  if (!debugging){return;}
  var code = "Deze functie is nog niet ge"+String.fromCharCode(239)+"mplementeerd.\n";
  for(var i=0; i < arguments.length; i++) {
    code += arguments[i] + "\n";
  }
  alert(code);
}

function debugAlert(){
  if (!debugging){return;}
  var code = "";
  for(var i=0; i < arguments.length; i++) {
    code += arguments[i] + "\n";
  }
  window.status = code;
  alert(code);
}

function debugConfirm(){
  if (!debugging){return;}
  var code = "";
  for(var i=0; i < arguments.length; i++) {
    code += arguments[i] + "\n";
  }
  window.status = code;
  return confirm(code);
}