My Solution to Roller Coaster

[Omer Braha]

var text = 'Hello World!';

var div = document.getElementById('rollercoaster');

for(var i in text){

  var letterSpan = document.createElement('span');

letterSpan.appendChild(document.createTextNode(text[i]));

letterSpan.style.fontSize = 10+5*(text.length/2-Math.abs(text.length/2-i))+'px';

div.appendChild(letterSpan);

}