function   setDiscoveringBackgroundColor(obj) { obj.style.backgroundImage="url(http://www.periodproperty.co.uk/graphics/pp_bgnav_green.gif)"; return true; }
function   setBuyingBackgroundColor(obj)      { obj.style.backgroundImage="url(http://www.periodproperty.co.uk/graphics/pp_bgnav_yellow.gif)"; return true; }
function   setBooksBackgroundColor(obj)       { obj.style.backgroundImage="url(http://www.periodproperty.co.uk/graphics/pp_bgnav_blue.gif)"; return true; }
function   setShoppingBackgroundColor(obj)    { obj.style.backgroundImage="url(http://www.periodproperty.co.uk/graphics/pp_bgnav_brown.gif)"; return true; }
function   setInsuringBackgroundColor(obj)    { obj.style.backgroundImage="url(http://www.periodproperty.co.uk/graphics/pp_bgnav_purple.gif)"; return true; }
function   setSeekingBackgroundColor(obj)     { obj.style.backgroundImage="url(http://www.periodproperty.co.uk/graphics/pp_bgnav_red.gif)"; return true; }
function   setSellingBackgroundColor(obj)     { obj.style.backgroundImage="url(http://www.periodproperty.co.uk/graphics/pp_bgnav_blue.gif)"; return true; }
function unsetBackgroundColor(obj)            { obj.style.backgroundImage="url(http://www.periodproperty.co.uk/graphics/pp_bgnav_green.gif)"; return true; }