How To Get User To Select A Sheet And Use It Later In Macro

I have a workbook with several sheets. I have written a macro to check if the value in a column is matching with that in another column in another sheet and return the value in a preceding column in the second sheet into a preceeding column in the first sheet. The code looks likes this and seems to be working fine.

Sub Copy_Price_Code()
Dim Rw As Long
For Rw = 6 To Sheet6.UsedRange.Rows.Count

[Code] ....

However, there would be more sheets in the workbook in future and I need to edit the macro in such a way that the user can select the source and destination sheets which I could use in the above macro. I tried to do it as follows but its not working.

Sub Copy_Price_Code()
Dim Rw As Long
Dim Rw2 As Long
Dim Sourcesheet As String
Dim Destinationsheet As String
Sourcesheet = InputBox(Prompt:="Enter source sheet name. (example: Sheet1).", _

[Code] .......