Help with coding - RealWorld forums

I was wondering how to use Java Script, I know all the basic coding, I learned it in a website called "scratch" but it uses visual script codes, I don't know what to type for what. So... Can you help me? Thanks!

What script would you like to create?

I Would like to make this script: forever:If Mouse down = yes, Repeat Until <not>MouseDown> then switch costume to costume 2 costume
If Mouse Down = no then switch costume to costume 1

This would appear to be an "on click switch to another cursor". I'm also interested. Wondering if it can be done and if so, how to accomplish this.