/** 
 * Associative array holding the alt image tag text
 */
var altImgTags = new Array();
altImgTags["RIBA"]        = "THIS IS THE OFFICIAL CREST OF THE ROYAL INSTITUTE OF BRITISH ARCHITECTS";
altImgTags["MACBOOK"]     = "THIS SHOWS A COMPUTER USED FOR CAD AND VISUALISATION WORK IN ARCHITECTURE";
altImgTags["HEMPSTEAD1 "] = "THIS SHOWS A SINGLE STOREY EXTENSION TO A LISTED THATCHED COTTAGE";
altImgTags["HEMPSTEAD2 "] = "INTERIOR PHOTOGRAPH OF EXTENSION TO LISTED THATCHED COTTAGE";
altImgTags["WINDRUSH2"]   = "ELEVATION OF PROPOSED EXTENSION TO WINDRUSH, A GRADE 2 LISTED COTTAGE";
altImgTags["WINDRUSH3"]   = "SKETCH OF PROPOSED EXTENSION TO WINDRUSH";
altImgTags["PASADENA1"]   = "PERSPECTIVE SKETCH OF REMODELLING OF SINGLE STOREY HOUSE IN PASADENA";
altImgTags["PASADENA2"]   = "PERSPECTIVE SKETCH OF REMODELLING OF SINGLE STOREY HOUSE IN PASADENA";
altImgTags["PASADENA5"]   = "PERSPECTIVE SKETCH OF REMODELLING OF SINGLE STOREY HOUSE IN PASADENA";
altImgTags["POLLARDS1"]   = "INTERIOR PHOTO OF NEW KITCHEN EXTENSION TO GRADE 2 LISTED FORMER MERCHANTS HOUSE";
altImgTags["POLLARDS2"]   = "INTERIOR PHOTO OF NEW KITCHEN EXTENSION TO GRADE 2 LISTED FORMER MERCHANTS HOUSE";
altImgTags["POLLARDS"]    = "EXTERIOR PHOTO OF NEW KITCHEN EXTENSION TO GRADE 2 LISTED FORMER MERCHANTS HOUSE";
altImgTags["ASCHAM1"]     = "SECTIONAL DRAWING SHOWING NEW BEDROOM EXTENSION TO 1830'S END OF TERRACE HOUSE";
altImgTags["GROVE"]       = "INTERIOR PHOTO OF REAR EXTENSION TO 1930'S SEMI DETACHED HOUSE";
altImgTags["GROVE3"]      = "EXTERIOR PHOTO OF REAR EXTENSION TO 1930'S SEMI DETACHED HOUSE";
altImgTags["GROVE4"]      = "INTERIOR PHOTO OF REAR EXTENSION TO 1930'S SEMI DETACHED HOUSE";
altImgTags["GROVE5"]      = "INTERIOR PHOTO OF REAR EXTENSION TO 1930'S SEMI DETACHED HOUSE";
altImgTags["StMARKS"]     = "SKETCH ELEVATIONS FOR PROPOSED NEW MULTIPURPOSE BUILDING FOR AN INDEPENDENT COLLEGE";
altImgTags["HARRY"]       = "INTERIOR PHOTO OF DOUBLE HEIGHT CORRIDOR TO NEW SCHOOL EXTENSION";
altImgTags["HARRY2"]      = "EXTERIOR VIEW OF ENTRANCE TO NEW SCHOOL EXTENSION";
altImgTags["WILB2"]       = "GABLE WALL PHOTO OF NEW PRIMARY SCHOOL";
altImgTags["WILB4"]       = "DETAIL OF ELEVATION OF NEW PRIMARY SCHOOL";
altImgTags["WILB7"]       = "PERSPECTIVE SKETCH OF ENTRANCE TO NEW PRIMARY SCHOOL";
altImgTags["INDIGOPLANT"] = "PHOTO SHOWING CULTIVATION OF WOAD IN SUSTAINABLE PRODUCTION OF INDIGO";
altImgTags["INDIGOVAT"]   = "PHOTO SHOWING A VAT OF SUSTAINABLY PRODUCED INDIGO DYE";
altImgTags["AMERSHAM1"]   = "PHOTO SHOWING EXTERIOR OF NEW JEWELLERY STORE";
altImgTags["AMERSHAM2"]   = "PHOTO SHOWING EXTERIOR OF NEW JEWELLERY STORE";
altImgTags["BORLEY"]      = "PHOTO SHOWING DETAIL OF PROPOSED BARN CONVERSION";
altImgTags["LAVENHAM1"]   = "PHOTO SHOWING DETAIL OF OAK BRACKETS TO LISTED HOUSE";
altImgTags["LAVENHAM2"]   = "PHOTO SHOWING HALLWAY TO LISTED HOUSE";
altImgTags["LAVENHAM3"]   = "ELEVATIONS SHOWING PROPOSED RESTORATION TO LISTED HOUSE";
altImgTags["MEDICINE"]    = "PLAN OF NEW UNIVERSITY RESEARCH BUILDING SHOWING SPACE PLANNING TO RESEARCH AREAS";
altImgTags["HERTFORD"]    = "ELEVATION SHOWING PROPOSED NEW FOYER TO HIGH STREET CHURCH";
altImgTags["FCO1"]        = "AERIAL VIEW SHOWING FOREIGN & COMMONWEALTH OFFICE";
altImgTags["BARKWAY1"]    = "ELEVATION SHOWING ALTERATIONS TO GABLE WALL OF GRADE 2 LISTED HOUSE";
altImgTags["ARB4"]        = "THIS IS AN OFFICIAL LOGO OF THE ARCHITECTS REGISTRATION BOARD";
/**
 * Clears a Div so we can put other stuff in
 * it. From: http://www.daveshuck.com/blog/index.cfm/2006/10/19/InnerHTML-no-more--Swapping-content-using-the-DOM
 */
function wwwClearElement(obj) {
  while(obj.firstChild) obj.removeChild(obj.firstChild);
}
/**
 * This grabs the image in the righthand div and deletes it (using the wwwClearElement function above)
 * before placing another image there.
 */ 
function replaceImage(value){
  var targetDiv = document.getElementById("righthand")
  wwwClearElement(targetDiv);
  var pic = document.createElement("img");
  pic.src = "http://indigo-architecture.com/images/462_996699_"+value+".jpg";
  pic.alt = altImgTags[value];
  pic.title = altImgTags[value];
  targetDiv.appendChild(pic);
}