// Get height of browser window
function GetWindowHeight()
{
    // Browser window height
    var windowHeight = 0;
    
    // Get browser window height
    if (typeof(window.innerHeight) == 'number') {
        windowHeight = window.innerHeight;
	}
	else
	{
        if (document.documentElement && document.documentElement.clientHeight) {
            windowHeight = document.documentElement.clientHeight;
        }
        else
        {
            if (document.body && document.body.clientHeight) {
                windowHeight = document.body.clientHeight;
            }
        }
    }
    
    // Return browser window height
    return windowHeight;
}


// Register a link object when in Async mode
function RegisterLink(obj) 
{
    // Retrieving link elements
    var linkElements = document.getElementsByTagName('link');
    
    // Holds a value indicating whether or not to add the style sheet
    var addStylesheet = true;
    
    // Check if the style sheet is already present
    for (var i = 0; i < linkElements.length; i++)
    {
        if (linkElements[i].href == obj.href)
        {
            // Style sheet already present, do not add it again
            addStylesheet = false;
            break;
        }
    }
    
    // Add the style sheet if it is not already present
    if (addStylesheet)
    {
        // Creating a link element
        var link = document.createElement('link');
        link.href = obj.href;
        link.rel = obj.rel;
        link.type = obj.type;
        
        // Adding the link element to the head
        document.getElementsByTagName('head')[0].appendChild(link);
    }
}