<script language = "javascript">
obj = document.getElementById("graphics");
obj_txt = document.getElementById("graphics_txt");
obj.style.display = "none";
obj_txt.onclick=function(){
 if( obj.style.display == "none" ) {
  obj.style.display = "block";
  obj_txt.style.color = 'red';
 } else {
  obj.style.display = "none";
  obj_txt.style.color = 'blue';
 }
}
</script>
 <a href="#"  id="graphics_txt" obj.style.color = 'red' >Показать/скрыть графики </a>
<div id="graphics">