function fnRollIn(button){
  document.getElementById(button).src="http://www.heathclaibornegallery.bookthecapitol.com/images/"+ button +"_g.gif";
 }

 function fnRollOut(button){
  document.getElementById(button).src="http://www.heathclaibornegallery.bookthecapitol.com/images/"+ button +".gif";
 }