How do I change a photos file type or make it smaller?

I got sent an email with some photos in but i cant add them to my facebook because either they are the wrong type or they are to big. They were sent to me using adobe how can i fix them?How do I change a photos file type or make it smaller?
Here is a free on line photo resizer i have used it and found it easy to use and offering a good free service. no software download needed.

http://webresizer.com



Here is the easy way to save photos as jpg/jpeg (same thing) files. Right click on the photo click ';save picture as'; check the box at the bottom is set to jpg and ';save'; and the file is automatically saved as jpg.