Rotating a picture?

[Tim Hart]

Hey everyone,
	I am doing somthing with rotating picture.  I know I can rotate an 
image a set amount with a button with the rotate command.  Like:

on mouseup
     rotate image "hello" by 90
end mouseup

My question is, is there a way to have the user drag something and have 
the image rotate?  Maybe like a slider?  I am not sure about sliders, I 
have never used them or know how to make them.  Any help or code would 
be appreciated.  Thanks.