document.getElementById('changeTextSize').style.display = 'inline';
var textSizes = new Array("70%", "85%", "100%", "120%", "140%", "160%", "200%");
var currentTextSize = 2;
function changeTextSize(sizeChange){

switch (sizeChange) {
  case -1:
   if ( currentTextSize + sizeChange < 0 || currentTextSize + sizeChange >= textSizes.length ) {
return;
}
    break;
  case 1:
 if ( currentTextSize + sizeChange < 0 || currentTextSize + sizeChange >= textSizes.length ) {
return;
}
    break;
  default:
    currentTextSize = 2;
    sizeChange=0;
    break;
}

var fliess = document.getElementById('fliess');
currentTextSize = currentTextSize + sizeChange;
fliess.style.fontSize = textSizes[currentTextSize];
}

changeTextSize(0);