So, I'm standing before a little web-dev issue that I can't figure out right now (yes, it is for OmnomIRC).
I need to write a function (JS) that returns true if:
 - This is the oirc instant of the currently open tab
 - If there is no oirc instant on the current tab if it is the instant of the last oirc visited
And false otherwise.

So basically I need to somehow detect stuff cross-tab

Any ideas on how to do so?
I thought about somehow the tabs registering themselves in local storage etc but idk, there is probably some better way....

What if the 1 to over 9000 chance happens and two tabs have the same id?
Ok, i think that chance is small enough to ignore - luckily I already have focus handlers making the whole thing easier! Thanks!
EDIT: ok, i have the following code now (and it works!)

tabId = '';
function getRandomTabId(){
tabId = Math.random().toString(36);
setCookie('OmnomBrowserTab',tabId,1);
}
function isCurrent(){
if(getCookie('OmnomBrowserTab')==tabId){
return true;
}
return false;
}
function registerFocusHandler(){
focusHandlerRegistered = true;
window.self.addEventListener('blur',function(){
bIsBlurred = true;
},false);
window.self.addEventListener('focus',function(){
setCookie('OmnomBrowserTab',tabId,1);
bIsBlurred = false;
},false);
}
to check if it is the current i just have to do isCurrent() now!

the problem is that i don't know the other ids and i have no way of knowing except have like a cookie grow indefenetley with all keys, i'll do what jim said, i'll add in adition to that random string the current timestamp in milliseconds, the chance is now far smaller for the same id!

I just did
tabId = Math.random().toString(36)+(new Date()).getTime().toString();