looking for a script to count the number of online visitors

I am looking for a script to count number of online visitors. I found one
for example for this site
http://radarurl.com/url/balatarin.com
but investigating if there is better than it.the statistic is good but I have
problem in browsing its page

 

You can give Statcounter a try. This gives you a clear picture of online visitors.

 

I used to use it before. Its great tracking tool if you need real time data. If you don't need real time tracking then Google Analytics is your choice