function newImage(arg) {
	if (document.images) {
		rslt = new Image();
		rslt.src = arg;
		return rslt;
	}
}

function changeImages() {
	if (document.images && (preloadFlag == true)) {
		for (var i=0; i<changeImages.arguments.length; i+=2) {
			document[changeImages.arguments[i]].src = changeImages.arguments[i+1];
		}
	}
}

var preloadFlag = false;
function preloadImages() {
	if (document.images) {
		btn1_over = newImage("/images/btn1-over.jpg");
		btn2_over = newImage("/images/btn2-over.jpg");
		btn3_over = newImage("/images/btn3-over.jpg");
		btn4_over = newImage("/images/btn4-over.jpg");
		btn5_over = newImage("/images/btn5-over.jpg");
		btn6_over = newImage("/images/btn6-over.jpg");
		btn7_over = newImage("/images/btn7-over.jpg");
		btn8_over = newImage("/images/btn8-over.jpg");
		btn9_over = newImage("/images/btn9-over.jpg");
	    sponsor_Chemtrec_over = newImage("/images/sponsor_Chemtrec-over.jpg");
		sponsor_ACC_over = newImage("/images/sponsor_ACC-over.jpg");
		sponsor_AAR_over = newImage("/images/sponsor_AAR-over.jpg");
		sponsor_RFA_over = newImage("/images/sponsor_RFA-over.jpg");
		sponsor_TCLI_over = newImage("/images/sponsor_TCLI-over.jpg");
		sponsor_NTTC_over = newImage("/images/sponsor_NTTC-over.jpg");
		sponsor_NACD_over = newImage("/images/sponsor_NACD-over.jpg");
		preloadFlag = true;
	}
}



function wopen(url, name, w, h)
{
  // Fudge factors for window decoration space.
  // In my tests these work well on all platforms & browsers.
  //w += 32;
  //h += 96;
  wleft = (screen.width - w) / 2;
  wtop = (screen.height - h) / 2;
 nheight =  screen.height - 170;
  // IE5 and other old browsers might allow a window that is
  // partially offscreen or wider than the screen. Fix that.
  // (Newer browsers fix this for us, but let's be thorough.)
  if (wleft < 0) {
    w = screen.width;
    wleft = 0;
  }
  if (wtop < 0) {
    h = screen.height;
    wtop = 0;
  }
  var win = window.open(url,
    name,
    'width=' + 920+ ', height=' + nheight + ', ' +
    'left=' + wleft+ ', top=' + 0 + ', ' +
    'screenX=' + wleft+ ', screenY=' + 0 + ', ' +
    'left=' + wleft + ', ' +
    'toolbar=no, scrollbars=yes, resizable=no, status=no, copyhistory=yes, location=no, menubar=yes');
  
  var offset = (navigator.userAgent.indexOf("Mac") != -1 || 
                  navigator.userAgent.indexOf("Gecko") != -1 || 
                  navigator.appName.indexOf("Netscape") != -1) ? 0 : 4;
    win.moveTo(wleft, -offset);
    win.resizeTo(920, screen.availHeight + (2 * offset));



  win.focus();
}