function show_search() 
{ 
  if (link_hide.className == "show") {
    link_hide.className  = "hide";
    search_field.style.display = "block";
  } else {
    link_hide.className  = "show";
    search_field.style.display = "none";
  }
}

function setup_vars() 
{
  link_hide = document.getElementById("hide-search");
  search_field = document.getElementById("search-field");
}

window.onload = setup_vars;