This is a tough one. What you want to do is set a cookie. Cookies are easy to set in flash. What you want to do is put the main variables inside the cookie, health, level, position on map, what quests are done, ect.
Here is how to set a cookie:
cookie = SharedObject.getLocal("mycookie");
// of course you can replace mycookie with whatever you want
cookie.data.var1 = "Variable one";
//you must use the same variable name, in my case it is cookie, declared on line 1
cookie.data.var2 = "Variable Two";
cookie.data.var3 = "Variable Three";
cookie.flush()
//frees up some memory. Not really needed, it just should be there.
You can have as many variables as you want in a cookie. Up to about 10mb I believe, thats around 3000 variables.
To set the variables its just
cookievariable.data.variablename= "variable value";
Now to load the values its this:
cookie = SharedObject.getLocal("legacy");
var1 = cookie.data.var1;
var2= cookie.data.var2;
var3 = cookie.data.var3;
And thats that!