Springs, should i change them?

[halistan]

OK,
i posted this on the other page but no one has answered yet...i'm feeling no love here :-) but anyway, i am thinking about having my struts changed because they are wearing out and the ride of my car is getting really bumpy. I would like it to get back to it's ld nice smooth self but some members here in the past have said that changing just the struts on thier SVX's didn't help much and that they thought you might have to change the springs too. Do springs go bad? If so, when should they be changed? Is there any way to tell if the springs need to be changed as well, because if i don't have to i don't want to (too expensive) but if they do go bad i might as well do it when i change the struts. Can anyone shed some light on this subject for me?

~Ray