Basically, this script checks if the user is running a certain addon, if yes, it shows an alert... the problem is after it shows the alert Firefox's spinning wheel keeps spinning like it's waiting for something. And if I refresh the page the script does not work...
This is the code:
<script language="javascript">
var isInstalled = false;
function run_if_true() {
isInstalled = true;
document.write("Your addon is installed\n<br>");alert("a");
}
function check_installed() {
if (isInstalled==false) {
document.write("Not installed"); // You can instead have an alert here
} else {
document.write("is installed");
}
}
</script>
</head>
<body onload="javascript:check_installed()">
testing!
<img src="chrome://fil/content/sd.gif"
width="0"
height="0"
onload="javascript: run_if_true()"
style="visibility:hidden">
</body>
</html>
After calling document.write(), you need a document.close().
See this link.