var oldStyle;
function changeStyle (newStyle) {
  if (oldStyle) {
    if (newStyle!=oldStyle) {
      	if (document.getElementById(newStyle).className == "one") {
    		  document.getElementById(oldStyle).className = "one";
    		  document.getElementById(newStyle).className = "two";
  	} 
  	else {  
  	}
    }	
    oldStyle=newStyle;
  }
  else {
    document.getElementById(newStyle).className = "two";
    oldStyle=newStyle;
  }   
}