Okay we've now got the browser writing out the details to the page. Now lets look at reading this information into flash. First of all remember that flash reads in variables in the format &name=value so in the above examples the screen height is written &height=768 . Now when I was looking at a few other tutorials which talk about reading these into flash, they have extra functions to add the & later. I found this to be troublesome and didn't always work. So I make myself add it at the start, this way I know the variables will read into flash correctly.