function websitedev() {
    hideAll(); 
    document.getElementById("submenu_websitedev").style.visibility='visible';
  }

  function seo() {
    hideAll(); 
    document.getElementById("submenu_seo").style.visibility='visible';
  }

  function sem() {
    hideAll(); 
    document.getElementById("submenu_sem").style.visibility='visible';
  }

  function otherservices() {
    hideAll(); 
    document.getElementById("submenu_otherservices").style.visibility='visible';
  }

  function portfolio() {
    hideAll(); 
    document.getElementById("submenu_portfolio").style.visibility='visible';
  }

  function hideAll() { 
    document.getElementById("submenu_websitedev").style.visibility='hidden'; 
    document.getElementById("submenu_seo").style.visibility='hidden'; 
    document.getElementById("submenu_sem").style.visibility='hidden'; 
    document.getElementById("submenu_otherservices").style.visibility='hidden'; 
    document.getElementById("submenu_portfolio").style.visibility='hidden'; 
  }