style.display = "block" not working for divs

Trying to use div style.display = "hidden" / "block"   the hidden works but the block does not and it sends me to the top of the web browser?? It works both in firefox and Chrome just not in I.E.?

 document.getElementById("Registration").style.display = "block";
 document.getElementById("RegistrationBottom").style.display = "block";
  //document.getElementById("Registration").style.display = "inline-block";
 //document.getElementById("RegistrationBottom").style.display = "inline-block";
 
 var x  = document.getElementById("Registration").style.display = "block";
 x.style.display = "block";
 var z  = document.getElementById("RegistrationBottom").style.display = "block";

thanks

Natale