var fields_array = new Array("field1","field2","field3","field4","field5","field6","field7","field8");// Put the id's of your hidden divs in this array

function displayFields(the_field){
	 if (document.getElementById(the_field).style.display==""){
	   document.getElementById(the_field).style.display = "none";return
  }
  for (i=0;i<fields_array.length;i++){
	   var my_field = document.getElementById(fields_array[i]);
	   my_field.style.display = "none";
	 }
  document.getElementById(the_field).style.display = "";
}