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Modern browsers in their default settings are blocking pop up windows. A simple window.open will not open a pop-up as most probably it will be blocked. But what to do if you need to show a special offer or something like this?

I’d suggest you to open a window on user action, e.g. clicking a button or moving mouse. I’ve copied this script from the Internet and successfully using it to enable pop-ups on clicking the links.

<script type=”text/javascript” language=”javascript”>
<!– //
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)
}

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){
return “”
}

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”)
winLeft = (screen.width – winWidth)/2
if (winLeft>0 & winTop>0)
winLocation =  “,screenX=” + winLeft + “,left=” + winLeft
+ “,screenY=” + winTop + “,top=” + winTop
else
winLocation = “”
return winLocation
}
//–>
// –>
</script>

Script usage is the following:

onClick=”javascript:openPopWin(‘Your URL’,Width,height,”,pixels from screen left to window left,pixels from screen top to window top)”

This will allow you to open a window and it is not blocked with browsers. If you have a more elegant solution, you’re welcome to post it here.

Here is a small piece of code that allows to reload a page only once. This is necessary to prevent some data being cached and this is the only solution I found good for my needs. Meta tag nocache did not save me, and meta tag refresh does not allow to refresh the page only once. So here is the code:

<script>
var reloaded = false;
var loc=”"+document.location;
loc = loc.indexOf(“?reloaded=”)!=-1?loc.substring(loc.indexOf(“?reloaded=”)+10,loc.length):”";
loc = loc.indexOf(“&”)!=-1?loc.substring(0,loc.indexOf(“&”)):loc;
reloaded = loc!=”"?(loc==”true”):reloaded;

function reloadOnceOnly() {
if (!reloaded)
window.location.replace(window.location+”?reloaded=true”);
}
reloadOnceOnly();
</script>

I found this in Google, but I had to spend some hours before I did it. So I think this article will be helpful for you.

If you’re hotlinking images from other servers (this is often used when adding banner codes), you might face the situation when remote server becomes unavailable. This will spoil your site look, if you don’t add a simple code, that allows to solve this issue.
<img src="BANNER URL(REMOTE)" onError="this.src='LOCAL URL SHOWN ON REMOTE SERVER ERROR'" height=31 width=88>

This simple code will save you from worrying on remote server uptime. That’s also a nice solution for showing remote server uptime – if you cannot get an image from remote server, the server shoulf be experiencing problems. You this and you’ll forget about banners with X signs.