Interface scripting -> Reading panels

Hi,
I am trying to script an interface for a script and am running into trouble.

Firstly my specific problem.
I generated a panel in which the user can chose a folder.
This works fine. I did this in the following way:


import bpy
from math import sin,cos,sqrt,exp


class OBJECT_PDB_Panel(bpy.types.Panel):
    bl_label = "PDB Blender"
    bl_space_type = "PROPERTIES"
    bl_region_type = "WINDOW"
    bl_context = "render"

    def draw(self, context):
        layout = self.layout
        scn = bpy.context.scene

        row = layout.row()
        row.label(text="Load a PDB file ...")
        layout.operator( "fp.button_load_file" )

       
        row = layout.row()
        row.label(text="Ausgabepfad")
        row = layout.row()
        row.prop(scn, "entry_max_atoms")

       
        row = layout.row()
        row.label(text="Ball precision (number of sectors)")
        row = layout.row()
        row.prop(scn, "entry_sectors_azimuth")
        row.prop(scn, "entry_sectors_zenith")


        row = layout.row()
        row.label(text="Scaling factors")
        row = layout.row()
        row.prop(scn, "entry_ball_radius")
        row.prop(scn, "entry_distances")


        row = layout.row()
        row.label(text="Sticks connecting balls")
        row = layout.row()
        row.prop(scn, "entry_sticks_yesno")
        row = layout.row()
        row.prop(scn, "entry_sticks_sectors")
        row.prop(scn, "entry_sticks_radius")
       

        row = layout.row()
        row.label(text="Center of the whole scene")
        row = layout.row()
        row.prop(scn, "entry_scene_x")
        row.prop(scn, "entry_scene_y")
        row.prop(scn, "entry_scene_z")
       
       
       
       

        row = layout.row()
        row = layout.row()
        row = layout.row()
        layout.operator( "fp.button_start" )
 

class CLASS_Start_Button(bpy.types.Operator):
    bl_idname = "fp.button_start"
    bl_label = "Start ..."
   
    def execute(self, context):
        scn = bpy.context.scene
        plot("Button Start")
        return {'FINISHED'}
   
   
class CLASS_Load_file__Button(bpy.types.Operator):
    bl_idname = "fp.button_load_file"
    bl_label = "Load file ..."
   
    def execute(self, context):
        scn = bpy.context.scene
        plot("Button Load File")
        return {'FINISHED'}


def register():
    bpy.utils.register_class(OBJECT_PDB_Panel)
    bpy.utils.register_class(CLASS_Start_Button)
    bpy.utils.register_class(CLASS_Load_file__Button)
   

def unregister():
    bpy.utils.unregister_class(OBJECT_PDB_Panel)
    bpy.utils.unregister_class(CLASS_Start_Button)
    bpy.utils.unregister_class(CLASS_Load_file__Button)


if __name__ == "__main__":

    #bpy.types.Scene.entry_max_atoms       = bpy.props.IntProperty (name="", default=5000, description = "Number of max. atoms")
    bpy.types.Scene.entry_max_atoms       = bpy.props.StringProperty (name="", subtype='DIR_PATH')
    bpy.types.Scene.entry_sectors_azimuth = bpy.props.IntProperty (name="Azimuth", default=16, description = "")
    bpy.types.Scene.entry_sectors_zenith  = bpy.props.IntProperty (name="Zenith", default=16, description = "")
   
    bpy.types.Scene.entry_ball_radius     = bpy.props.FloatProperty (name="Ball", default=1.0, description = "Ball radius")
    bpy.types.Scene.entry_distances       = bpy.props.FloatProperty (name="Distance", default=1.0, description = "All distances")
   
    bpy.types.Scene.entry_scene_x         = bpy.props.FloatProperty (name="X", default=0.0, description = "X coordinate")
    bpy.types.Scene.entry_scene_y         = bpy.props.FloatProperty (name="Y", default=0.0, description = "Y coordinate")
    bpy.types.Scene.entry_scene_z         = bpy.props.FloatProperty (name="Z", default=0.0, description = "Z coordinate")
       
    bpy.types.Scene.entry_sticks_yesno    = bpy.props.BoolProperty (name="Yes connect balls", default=False, description = "Yes or no")   
    bpy.types.Scene.entry_sticks_sectors  = bpy.props.IntProperty (name="Sector", default=16, description = "")       
    bpy.types.Scene.entry_sticks_radius   = bpy.props.FloatProperty (name="Radius", default=1.0, description = "")
       
    register()


The user can select a directory path. Now I want to use this path as an ouput path for another script I wrote. As a test I tried to simpyl implement a button which would print the output path to the console but I failed.
How can I grab the information the user inputs into this field?