Go to your user CP to edit your signature.
Take out what you have there now.
Put in the chart icon
highlight the text (;chart; where the ; is : ) for the chart icon and click the box that looks like the world with a chain to insert a link.
paste the url for your charting homepage (http://www.fertilityfriend.com/home/2007db
) into the box, remember to only have one http://
you can check your sig by clicking preview signature in the user CP, if it looks right click save.