function change_size(height)
{
    new_height = getHeight(false);
    // document.getElementById('wrapper').style.height = height > new_height ? height + 'px' : new_height + 'px';
}

// get the height of the window / page
function getHeight(isFull)
{
    // make sure isFull exists
    isFull = (isFull == undefined) ? true : isFull;
    
    // init vars
    var oh = document.documentElement.offsetHeight != undefined ? document.documentElement.offsetHeight : (isFull ? 0 : 10000000);
    var ch = document.body.clientHeight != undefined ? document.body.clientHeight : (isFull ? 0 : 10000000);
    var ih = window.innerHeight != undefined ? window.innerHeight : (isFull ? 0 : 10000000);
    var value = false;
    
    // get the wanted value
    value = isFull && oh >= ch && oh >= ih ? oh : (!isFull && oh <= ch && oh <= ih ? oh : value);
    value = isFull && ch >= oh && ch >= ih ? ch : (!isFull && ch <= oh && ch <= ih ? ch : value);
    value = isFull && ih >= ch && ih >= oh ? ih : (!isFull && ih <= ch && ih <= oh ? ih : value);
    
    // return the value
    return value == 0 ? false : value;
}