How do you change an image's size?

[Czechs Mex]

I was going to post some screenshots for someone's game, but I don't want the pics to be completely massive. Anyone know offhand if there's an easy way to scale this down (other than manually doing it in paint or something)?

Thanks.

[altoecko]

If you upload them through Photobucket.com they instantly reduce them to a decent size.

[Omnislash024]

Yup, but I was looking on here and here doesn't seem to be a way to manually do it on this forum. You enter the width and height codes inside the img codes, but it just creates text.