57254 Very, Very Easy PHP Script

I need a script that I can put on my server that will randomly split the traffic to a Variable number of websites. Would prefer this to pull the data for the websites from a text file like this: [login to view URL] [login to view URL] [login to view URL] So the first visitor would be directed to website A. the second visitor would be directed to website B. the third visitor would be directed to website C. etc... If I had 4 websites in the text file it would split traffic 4 ways. If I had 2 it would split it two ways. Etc Etc.