You need to download Celtx, which is free script-formatting software. Also, you should use regular punctuation in your action lines--get rid of the colons and use a period instead. Plus, you don't need to put exclamation points in parenthesis.
You have an interesting premise, but it isn't going to get read with all of the formatting errors. Also, most horror scripts are about 90 pages, so I suggest you cut some stuff to make this shorter.