var visibility_link_iphone = "none";
  if ((navigator.userAgent.indexOf('iPhone') != -1) ||  
	   (navigator.userAgent.indexOf('iPod') != -1)) {  
	   //document.location = "http://www.groovemaker.com/iphone/";  
		visibility_link_iphone = "block";
   }  

//alert (visibility_link_iphone);
document.getElementById('link_iphone').style.display=visibility_link_iphone;
//document.link_iphone.style.display=visibility_link_iphone;