Breaking up a string

I have a problem that might be easy to solve. I have a string I need to break up into 3 values.

<option value="<%=poll_id%>,<%=topic_id%>,<%=forum_id%>"><%=Poll_question%></option>

This is a drop down box and when I process the results I need to break this string down to 3 values

1.)    poll_id

2.)    topic_id

3.)    forum_id

I have totally flaked on how to do this.

yeah I got that far the part i am stuck on is spliting the values up.

poll_id = <%=poll_id%>

topic_id = <%=topic_id%>

forum_id = <%=foum_id%>

basicly what I am doing is adding a poll to my front page of my site using a list of polls from my forum. I am making a new page in the admin section to change these polls and want to just chose a poll to display from a drop down list. I have everything working but this string.