function affiche_menu(lemenu){
	if (lemenu == "location"){
		document.getElementById('location').style.visibility = "visible";
        document.getElementById('vente').style.visibility = "hidden";
        document.getElementById('agence').style.visibility = "hidden";
        document.getElementById('mnlocation').style.background = "url(images/menu-select.jpg) no-repeat left top";
        document.getElementById('mnvente').style.background = "url(images/gbmenu.jpg) no-repeat left top";
        document.getElementById('mnagence').style.background = "url(images/gbmenu.jpg) no-repeat left top";
    }
    else if(lemenu == "vente"){
            document.getElementById('location').style.visibility = "hidden";
            document.getElementById('vente').style.visibility = "visible";
            document.getElementById('agence').style.visibility = "hidden";
            document.getElementById('mnagence').style.background = "url(images/gbmenu.jpg) no-repeat left top";
            document.getElementById('mnvente').style.background = "url(images/menu-select.jpg) no-repeat left top";
            document.getElementById('mnlocation').style.background = "url(images/gbmenu.jpg) no-repeat left top";
    }
    else if(lemenu == "agence"){
            document.getElementById('location').style.visibility = "hidden";
            document.getElementById('vente').style.visibility = "hidden";
            document.getElementById('agence').style.visibility = "visible";
            document.getElementById('mnlocation').style.background = "url(images/gbmenu.jpg) no-repeat left top";
            document.getElementById('mnvente').style.background = "url(images/gbmenu.jpg) no-repeat left top";
            document.getElementById('mnagence').style.background = "url(images/menu-select.jpg) no-repeat left top";
    }
    else{
            document.getElementById('location').style.visibility = "hidden";
            document.getElementById('vente').style.visibility = "hidden";
            document.getElementById('agence').style.visibility = "hidden";
            document.getElementById('mnlocation').style.background = "url(images/gbmenu.jpg) no-repeat left top";
            document.getElementById('mnvente').style.background = "url(images/gbmenu.jpg) no-repeat left top";
            document.getElementById('mnagence').style.background = "url(images/gbmenu.jpg) no-repeat left top";
    }
}