var overlay = {

  click_on_overlay_hide: true,

  show_loading_image: false,

  loading_image: "/img/loading.gif",

  $: function(id){
    return document.getElementById(id);
  },

  init: function(){
    var ol_div = document.createElement("div");

    ol_div.id = "overlay";
    ol_div.style.display = "none";
    //ol_div.onclick = (this.click_on_overlay_hide)? overlay.hide : null;

    if(this.show_loading_image){
      var l_img = document.createElement("img");

      l_img.id = "overlay_img";
      l_img.src = this.loading_image;
      l_img.style.position = "absolute";
      l_img.style.top = (((window.innerHeight)? window.innerHeight : document.body.clientHeight) / 2) + "px";
      l_img.style.left = (((window.innerWidth)? window.innerWidth : document.body.clientWidth) / 2) + "px";

      ol_div.appendChild(l_img);
    }

    document.body.appendChild(ol_div);
  },

  show: function(){
    if(this.$("overlay")){
      this.$("overlay").style.display = "";
    }
  },

  hide: function(){
    if(overlay.$("overlay")){
      overlay.$("overlay").style.display = "none";
    }
  }

}


  function make_postString(myform)
  {
  for (var i = 0; i < myform.elements.length; i++)
  {
  if(!myform.elements[i].type)   // Undefined überlesen
    {
    continue;
    }
  var field_name  = myform.elements[i].name;
  if(myform.elements[i].type == "checkbox")
    {
    var field_value = myform.elements[i].checked;
    }
  else
    {
    var field_value = myform.elements[i].value;
    // Übergangslösung; für die Zukunft irgendwas mit UrlEncode
    // Alle Arten von Hochkommas entfernen
    field_value     = field_value.replace(/[\'\"]/g, '');

    }

  try
    { var check_pos   = field_name.indexOf("check_"); }
  catch(e) { check_pos = -1; }

  if(check_pos >=0)
    {
    field_name = field_name.substr(check_pos+6);
    if(field_value=="")
      {
      postString="!ERROR! Bitte Feld '"+field_name+"' ausfüllen";
      break;
      }
    }
  //  postString += field_name + "=" + encodeURIComponent(field_value);
  postString += field_name + "=" + escape(field_value);
  if (myform.elements.length - i > 1){ postString += "&"; }
  }
}


  function resizeDiv(container,div)
  {
    try
      {
      obj_div       = document.getElementById(div);
      obj_container = document.getElementById(container);
      if(obj_container && obj_div)
        {
        obj_div.style.height = "0px";
        obj_div.style.width  = "0px";
        obj_div.style.height = obj_container.clientHeight-2+"px";
        obj_div.style.width  = obj_container.clientWidth-2+"px";
        }
      }
    catch(e){}
  }
  
function popup(pgm,name,b,h)
{
var l = (screen.availWidth - b) / 2;
var t = (screen.availHeight - h) / 2;
var s1= "scrollbars,status=yes,resizable,width="+b+",height="+h;
var s2= ",screenX="+l+",screenY="+t+",left=" +l+",top="+t;
fmpopup=window.open(pgm, name, s1+s2);
fmpopup.focus();
}

function mypopup(pgm,name,b,h,windowparms)
{
var l = (screen.availWidth - b) / 2;
var t = (screen.availHeight - h) / 2;
var s1= windowparms;
var s2= ",width="+b+",height="+h+",screenX="+l+",screenY="+t+",left=" +l+",top="+t;
fmpopup=window.open(pgm, name, s1+s2);
fmpopup.focus();
}


function sleep(ms)
{
  var now = new Date();
  var exitTime = now.getTime() + ms;

  while(true)
  {
    now = new Date();
    if(now.getTime() > exitTime) return;
  }
}

function trim(str)
{
  return str.replace(/^\s+|\s+$/g, ''); 
}

// Checks that a string contains only numbers
function isNumber(str) {
  for(var position=0; position<str.length; position++){
	var chr = str.charAt(position)
        if  ( (chr < "0") || (chr > "9") ) 
              return false;
  };      
  return true;
};