function opacity(id, opacStart, opacEnd, millisec) {
    //speed for each frame
    var speed = Math.round(millisec / 100);
    var timer = 0;

    //determine the direction for the blending, if start and end are the same nothing happens
    if(opacStart > opacEnd) {
        for(i = opacStart; i >= opacEnd; i--) {
            setTimeout("changeOpac(" + i + ",'" + id + "')",(timer * speed));
            timer++;
        }
    } else if(opacStart < opacEnd) {
        for(i = opacStart; i <= opacEnd; i++)
            {
            setTimeout("changeOpac(" + i + ",'" + id + "')",(timer * speed));
            timer++;
        }
    }
}

//change the opacity for different browsers
function changeOpac(opacity, id) {
    var object = document.getElementById(id).style;
    object.opacity = (opacity / 100);
    object.MozOpacity = (opacity / 100);
    object.KhtmlOpacity = (opacity / 100);
    object.filter = "alpha(opacity=" + opacity + ")";
}

function shiftOpacity(id, millisec) {
    //if an element is invisible, make it visible, else make it ivisible
    if(document.getElementById(id).style.opacity == 0) {
        opacity(id, 0, 100, millisec);
    } else {
        opacity(id, 100, 0, millisec);
    }
}



function blendimage(divid, imageid, imagefile, millisec) {
    var speed = Math.round(millisec / 100);
    var timer = 0;

    //set the current image as background
    document.getElementById(divid).style.backgroundImage = "url(" + document.getElementById(imageid).src + ")";

    //make image transparent
    changeOpac(0, imageid);

    //make new image
    document.getElementById(imageid).src = imagefile;

    //fade in image
    for(i = 0; i <= 100; i++) {
        setTimeout("changeOpac(" + i + ",'" + imageid + "')",(timer * speed));
        timer++;
    }
}




function startTimeout(showNoOne) {
//alert('test');
  var speed=8000; // was 6000

  if (showNoOne==true) {
    for(state=1; state<=4; state++) {
      testId = setTimeout("setPhotoBoxState("+state+")", speed*(state-1));
    }

    startAgain = setTimeout("startTimeout(true)", speed*(state-1));
  }
  else {

    for(state=2; state<=4; state++) {
      testId = setTimeout("setPhotoBoxState("+state+")", speed*(state-1));
    }

    startAgain = setTimeout("startTimeout(true)", speed*(state-1));
  }
}


function dw_changeProp(objName,thex,theProp,theValue) { //v3.0
	// originally by macromedia
  var obj = document.getElementById(objName);
  if (obj && (theProp.indexOf("style.")==-1 || obj.style)) eval("obj."+theProp+"='"+theValue+"'");
}


function setPhotoBoxState(state) {

  lastState = state - 1;
  if (lastState < 1) { lastState = 4; }

  x = '';
  // set the background to the last image displayed to eliminate flicker
  document.getElementById('blenddiv').style.backgroundImage = "url("+x+"'images/homepage/"+lastState+".jpg')";
  // set the image

  arrAltTags = new Array();
  arrAltTags[1] = 'A large training/conference room';
  arrAltTags[2] = 'CCT Venues-Barbican';
  arrAltTags[3] = 'A training room';
  arrAltTags[4] = 'A training room';
  arrAltTags[4] = 'A conference suite';

  strAltTag = 'alt="'+arrAltTags[state]+'"';

  dw_changeProp('photo_holder','','innerHTML','<img name=photos_holder id=photos_holder src='+x+'images/homepage/'+state+'.jpg '+strAltTag+' border=0>','SPAN');


  changeOpac(0,'photos_holder');

  shiftOpacity('photos_holder', 1000);

}


function currentOpac(id, opacEnd, millisec) {
    //standard opacity is 100
    var currentOpac = 100;

    //if the element has an opacity set, get it
    if(document.getElementById(id).style.opacity < 100) {
        currentOpac = document.getElementById(id).style.opacity * 100;
    }

    //call for the function that changes the opacity
    opacity(id, currentOpac, opacEnd, millisec)
}