//Features = 'toolbar=1,scrollbars=1,location=1,status=1,menubar=1,resizable=1'
var popWin = null  // use this when referring to pop-up window
var winCount = 0
var winName = "popWin"
function openPopWin(winURL, winWidth, winHeight, winFeatures, winLeft, winTop) {
	var d_winLeft = 20	// default, pixels from screen left to window left
	var d_winTop = 20	// default, pixels from screen top to window top
	winName = "popWin" + winCount++	//unique name for each pop-up window
	closePopWin()		// close any previously opened pop-up window
	if (openPopWin.arguments.length >= 4)	//any additional features?
		winFeatures = "," + winFeatures
	else
		winFeatures = ""
	if (openPopWin.arguments.length == 6)	// location specified
		winFeatures += getLocation(winWidth, winHeight, winLeft, winTop)
	else
		winFeatures += getLocation(winWidth, winHeight, d_winLeft, d_winTop)
	popWin = window.open(winURL, winName, "width=" + winWidth
				+ ",height=" + winHeight + winFeatures)
	//if (popWin.opener == null) popWin.opener = self
	popWin.focus()
}
	
function closePopWin() {	// close pop-up window if it is open
	if (navigator.appName != "Microsoft Internet Explorer"
			|| parseInt(navigator.appVersion) >= 4)	// do not close if early IE
		if (popWin != null) if (!popWin.closed) popWin.close()
}

function getLocation(winWidth, winHeight, winLeft, winTop) {
	var winLocation = ""
	if (winLeft < 0)
		winLeft = screen.width - winWidth + winLeft
	if (winTop < 0)
		winTop = screen.height - winHeight + winTop
	if (winTop == "cen")
		winTop = (screen.height - winHeight)/2 - 20
	if (winLeft == "cen")
		winTop = (screen.width - winWidth)/2
	if (winLeft > 0 && winTop > 0)
		winLocation = ",screenX=" + winLeft + ",left=" + winLeft
					+ ",screenY=" + winTop + ",top=" + winTop
	else
		winLocation = ""
	return winLocation
}