GetParameterAsText(arcpy) does not work

I am new in this area. I was practicing the function GetParameterAsText(). I know that when you run the code (for example in PythonWin) it works like the function raw_input(), therefore it should show a small window where the user can input the required fields.

My problem is that I tried yesterday to use the function GetParameterAsText(), but I have this error, and I think it is about the libraries:

I used the example in the ArcGIS Help:
http://resources.arcgis.com/en/help/main/10.1/index.html#//018v00000047000000

*File “C:Python27ArcGIS10.2Libsite-packagespythonwinpywinframeworkscriptutils.py”,
line 322, in RunScript debugger.run(codeObject, main.dict,
start_stepping=0) File
“C:Python27ArcGIS10.2Libsite-packagespythonwinpywindebugger__init__.py”,
line 60, in run GetCurrentDebugger().run(cmd, globals,locals,
start_stepping) File
“C:Python27ArcGIS10.2Libsite-packagespythonwinpywindebuggerdebugger.py”,
line 655, in run exec cmd in globals, locals

File “C:WCGISGeog485Lesson1scriptspractice_4.py”, line 1, in
import os

File “C:Program Files
(x86)ArcGISDesktop10.2arcpyarcpymanagement.py”, line 2429, in
CopyFeatures raise e ExecuteError: Failed to execute. Parameters are
not valid. ERROR 000735: Input Features: Value is required ERROR
000735: Output Feature Class: Value is required Failed to execute
(CopyFeatures).*