Populate ArrayList 2 columns and keep a count in second column of each occurrence c#

[toniindigo]

I'm new to ASP.NET C#. Trying to create an ArrayList with 2 columns one for the value (string) and one for counting how many of each. While adding values I need to search the ArrayList to find if the value already exist, if so add 1, if not, add it to the array and set count column to 1. Can someone provide a bit of code sample? If there is a better approach then I'd like to hear it.