function Popup(url,w,h){
if(w > screen.availWidth){
    w = screen.availWidth-10;
    LeftPosition = 0;
  }else
    LeftPosition = (screen.availWidth) ? (screen.availWidth-w)/2 : 0;
if(h > screen.availHeight){
    h = screen.availHeight-30;
    TopPosition = 0;
  }else
    TopPosition = (screen.availHeight) ? (screen.availHeight-h)/2 : 0;

parameter = 'scrollbars=yes,toolbar=0,location=no,directories=no,status=0,menubar=no,resizable=yes,copyhistory=no,width='+w+',height='+h+',screenX='+LeftPosition+',screenY='+TopPosition+',top='+TopPosition+',left='+LeftPosition;
Fenster = window.open(url,'',parameter);
}

function GrossbildAnzeigen(Bild, Breite, Hoehe, UrlRoot){
      Popup(UrlRoot + 'Grossbild.php?Dateiname='+Bild+'&Breite='+Breite+'&Hoehe='+Hoehe, Breite + 60, Hoehe + 50);
    }

function InputTextAendern(Objekt,Text){
if(Objekt){
    if(Objekt.value == Text)
        Objekt.value = '';
      else if(Objekt.value == '')
        Objekt.value = Text;
  }
}


function TextAnfuegen(ObjektID, aTag, eTag) {
  var input = document.getElementById(ObjektID);
  input.focus();
  if(typeof document.selection != 'undefined') {
    var range = document.selection.createRange();
    var insText = range.text;
    range.text = aTag + insText + eTag;
    range = document.selection.createRange();
    if (insText.length == 0) {
      range.move('character', -eTag.length);
    } else {
      range.moveStart('character', aTag.length + insText.length + eTag.length);
    }
    range.select();
  }
  else if(typeof input.selectionStart != 'undefined')
  {
    var start = input.selectionStart;
    var end = input.selectionEnd;
    var insText = input.value.substring(start, end);
    input.value = input.value.substr(0, start) + aTag + insText + eTag + input.value.substr(end);
    var pos;
    if (insText.length == 0) {
      pos = start + aTag.length;
    } else {
      pos = start + aTag.length + insText.length + eTag.length;
    }
    input.selectionStart = pos;
    input.selectionEnd = pos;
  }
  else
  {
    var pos;
    var re = new RegExp('^[0-9]{0,3}$');
    while(!re.test(pos)) {
      pos = prompt("Einfügen an Position (0.." + input.value.length + "):", "0");
    }
    if(pos > input.value.length) {
      pos = input.value.length;
    }
    var insText = prompt("Bitte geben Sie den zu formatierenden Text ein:");
    input.value = input.value.substr(0, pos) + aTag + insText + eTag + input.value.substr(pos);
  }
}

function ObjektVerstecken(ID){
    document.getElementById(ID).style.visibility = 'hidden';
  }