Function Keywords

Im trying to create a function to where when I call the function, it returns the next keyword from the list, and the list is only a string of keywords split by comma's. I know how to split it, but I dont know how to have the function call out the next keyword.
keyword1,keyword2,keyword3,keyword4.Code:

<%=Function1(keyword)%> 'Will spit out Keyword 1

<%=Function1(keyword)%> 'Will spit out Keyword 2

<%=Function1(keyword)%> 'Will spit out Keyword 3

<%=Function1(keyword)%> 'Will spit out Keyword 4

Then I need it to start over again once it gets to the last function.
This function will be spread out across the page.