var showhide = document.getElementById('showhide')

showhide.style.cursor = 'pointer'
var leftnav = document.getElementById('left-nav')
var rightnav = document.getElementById('right-nav')

showhide.onclick = function() {
    if ((leftnav.style.display == "none") || (leftnav.style.display == "")) {
        leftnav.style.display="inline"
        rightnav.style.display="inline"
    } else {
        leftnav.style.display="none";
        rightnav.style.display="none";
    }
};