// Somewhere in your setup, do this:
JSObject jsHud = awesomium.WebView.CreateGlobalJavascriptObject("hud");
jsHud.Bind("OnMouseUp", false, OnMouseUp);
jsHud.Bind("OnMouseDown", false, OnMouseDown);
// and use the following JS: http://pastebin.com/sCRk259m


// Then make some functions:

protected void OnMouseDown(object sender, JavascriptMethodEventArgs e)
{
    bool mouseUpOverHUD = e.Arguments[0];
    MouseButton mouseButton = (MouseButton)(int)e.Arguments[1];

}


/// <summary>
/// Handle mouse up everywhere except the controls
/// </summary>
protected void OnMouseUp(object sender, JavascriptMethodEventArgs e)
{
    bool mouseUpOverHUD = e.Arguments[0];
    MouseButton mouseButton = (MouseButton)(int)e.Arguments[1];
    bool clickHandled = mouseUpOverHUD;

    if (mouseButton == MouseButton.LEFT)
    {

        if (!clickHandled && creatingEntityID != null)
        {
            // Have we just tried to build this guy?
            if (/*mouse.LeftButton == EnhancedButtonState.JUST_RELEASED &&*/ IsValidToBuildHere())
            {
                // Yes, build this now!
                BuildStructure();
                clickHandled = true;
            }
        }
    }
    else if (mouseButton == MouseButton.RIGHT && creatingEntityID != null)
    {
        OnCancelCreation();
    }

    if(!clickHandled)
    {
        selectionSystem.OnMouseUp(sender, mouseButton, theMouse);
    }
}