get height of socument code example
Example 1: javascript get element width
var width = document.getElementById('myID').offsetWidth;
var height = document.getElementById('myID'). offsetHeight;
Example 2: javascript get body height
var body = document.body,
html = document.documentElement;
var height = Math.max( body.scrollHeight, body.offsetHeight,
html.clientHeight, html.scrollHeight, html.offsetHeight );
Example 3: height of page selenium
Dimension initial_size = driver.manage().window().getSize();
int height = initial_size.getHeight();
int width = initial_size.getWidth();