JS - What is wrong here?

function menu(what, id){
      name = getElementById(id);
      if(what == "" || !isset(what)){
        alert("Something Wrong");
      }
      elseif(what == "over"){
        name.className = 'menu_over';
        name.style.cursor='pointer';
        name.style.cursor='hand';
        alert("heya babe!");
      }
      elseif(what == "out"){
        name.className = 'menu';
        name.style.cursor='default';
      }
      else{
        alert("Something Wrong");
      }
    }
    
    function click(link){
      location.href = link;
    }

<script>
function change(newClass, id) {
    identity=document.getElementById(id);
    identity.className='menu_'+newClass;
}
</script>
<style>
.first{
background: #ffffff;
}
.second{
background: #000000;
}
</style>
<div id="1" class="first" onMouseOver="change(second, 1)">Mouse Over Me</div>