Radio System Scripts [Not Working] ?

This is the place: http://www.roblox.com/Radio-System-Test-place?id=69780965 (It's uncopy-locked so you can see whats happening.

This is the order of the Model:

--[[
	- RadioModel (Model)
		-Script (Script)
			-ScreenGui
			
				-FRAME (Frame)
					-ScrollUpDown (Frame)
						-Choice_1 (TxtButton)
							-Script
						-Choice_2 (TxtButton)
							-Script
						-Choice_3 (TxtButton)
							-Script
						-Choice_4 (TxtButton)
							-Script
						-Choice_5 (TxtButton)
							-Script
						-Choice_6 (TxtButton)
							-Script
						-Choice_7 (TxtButton)
							-Script
					-AudioIDInsert (TxtBox)
					-Help (TxtButton)
					-SubmitButton (TxtButton)
					-AudioID (TxtLabel)
					
				-HELP (Frame)
					-Done (TxtButton)
						-Script
					-ImageLabel (ImgLabel)
					-Background (TxtLabel)
					-HeadTitle (TxtLabel)
					-Information (TxtLabel)
					
		-ClickPart (Part)
			-ClickDetector (ClickDetector)
			-Script
		-Music (Part)
			-Sound (Sound)
				-Script
		-Part (unnecessary)
		-Part (unnecessary)
--]]

The script below is the script in the "RadioModel.Script.ScreenGui.Frame.SubmitButton" (This Script is not working properly... Any fixes on this?) [I want the script to take the Audio ID that the player entered in the Text Box and put it at the end of "http://www.roblox.com/asset/?id=" and put it in "Sound.SoundID"

local Button = script.Parent
Frame = script.Parent.Parent


function onClick() 


Frame.Visible = false
a = script.Parent.Parent.AudioIDInsert.Text
game.Workspace.RadioModel.Music.Sound.SoundId="http://www.roblox.com/asset/?id=" .. a .. "" 

end 

Button.MouseButton1Click:connect(onClick)

The script below is the script in "RadioModel.ClickPart" (This Script is not working properly... Any fixes on this?) [I want the script to switch the visibility of the ScreenGui.Frame to true once the player clicks on the part] [I only want the GUI to be visible to the player who clicked the part ONLY though]

function onClicked(hit)
	check = hit.Parent:FindFirstChild("Humanoid")
if check ~= nil then
	local user = game.Players:GetPlayerFromCharacter(hit.Parent)

	user.PlayerGui.ScreenGui.Frame.Visible = true
	end
end
script.Parent.ClickDetector.MouseClick:connect(onClicked)

Thanks for anyone trying to help.