function switchMenu(obj) {



// Window dimensions:
var theWidth;
if (window.innerWidth)
theWidth=window.innerWidth;
else if (document.documentElement && document.documentElement.clientWidth)
theWidth=document.documentElement.clientWidth;
else if (document.body)
theWidth=document.body.clientWidth;


//var wdt = document.documentElement.clientWidth;
var lwdt = (theWidth/2);



var el = document.getElementById(obj);
if ( el.style.display != 'none' ) {
el.style.display = 'none';
}
else {
el.style.display = '';


var T=document.getElementById(obj);

lwdt = lwdt-(T.offsetWidth/2);
//lwdt = lwdt -250;//horizontal adjustment
el.style.left = lwdt+ 'px';



}
}