var max = 24
var min = 12 
function upSize() { 
size = parseInt(document.getElementById("story").style.fontSize) 
if (size != max) { 
size = size + 3 
} 
document.getElementById("story").style.fontSize = size + "px" 
} 
function downSize() { 
size = parseInt(document.getElementById("story").style.fontSize) 
if (size != min) { 
size = size - 2 
} 
document.getElementById("story").style.fontSize = size + "px" 
}