Would you say my strings are worn out and in need of replacement?

[Silverwolf]

Removed the strings from my recently purchased used bass and gave them a 20 hour soak in meths. Dried them and replaced them on the guitar, and now noticed that at least a couple of the strings have a few shiny marks where they meet up with the frets. Assume that when I replaced the strings, they got rotated around a bit, so the lower side of the string has now moved around to the side/top. Does this suggest heavy wear, or does this happen quite early in a string's life? Should I replace the strings, and if so how do I find out what gauge strings I have at the moment?

[johnm]

go out and buy a new set.... quick google
[url="http://www.newstrings.co.uk/acatalog/4-STRING.html"]http://www.newstrings.co.uk/acatalog/4-STRING.html[/url]
[url="http://www.stringsdirect.co.uk/products/4818-stagg_nickel_round_wound_budget_bass_guitar_strings"]http://www.stringsdirect.co.uk/products/48..._guitar_strings[/url]

Edited October 23, 2009 by johnm