Closing tab in Firefox

Hi, I have a number of PHP scripts that I run purely on my own system and I am using Firefox, and currently get them to open new tabs each time they run....what I would like to do is to close the tab once they have finished running, as if I am away for a few days I can end up with over 100 open tabs. I do need to run them in a browser, as sometimes they do not finish running properly, and I need to be aware of which ones and why they failed. I have tried google and all I come up with is closing the entire browser and not just a tab. Any suggestions really woudl be most appreciated Cheers Alexis