function checkUserDevice(){

try
  {
  if((navigator.userAgent.match(/iPhone/i)) || (navigator.userAgent.match(/iPod/i)) || (navigator.userAgent.match(/iPad/i))) {  
  $novisits = getCookie('numberOfVisits');
    if ($novisits == ""){
      $novisits = 0;
    }
    if ($novisits <= 2){
      document.getElementById('iOS').style.display = 'block';
      setCookie("numberOfVisits",parseInt($novisits) + 1,1);
    }
  }
  }
catch(err)
  {
  //Handle errors here
  }
}



function setCookie(c_name,value,expiredays)
{
  var exdate=new Date();
  exdate.setDate(exdate.getDate()+expiredays);
  document.cookie=c_name+ "=" +escape(value)+
  ((expiredays==null) ? "" : ";expires="+exdate.toUTCString());
}


function getCookie(c_name)
{
if (document.cookie.length>0)
  {
  c_start=document.cookie.indexOf(c_name + "=");
  if (c_start!=-1)
    {
    c_start=c_start + c_name.length+1;
    c_end=document.cookie.indexOf(";",c_start);
    if (c_end==-1) c_end=document.cookie.length;
    return unescape(document.cookie.substring(c_start,c_end));
    }
  }
return "";
}