Find averages for selected ranges based on inputbox criteria

Hi I'm new to this but I have a spreadsheet with phone call lengths (in seconds) for 3 separate incoming phone lines. I am monitoring the amount of time in seconds that each call takes, row by row, and need to determine average call times in seconds for particular days and for the month.

I would like to be able to use an INPUTBOX to ask user for date and phone line # (1,2,3 or All Lines) and display average call times for input date. I would like to display the result in a MSGBOX with the option to save result to unused area in spreadsheet

The following ranges contain the date of each phone call (format "mmm. d")
(Phone Line 1) A6:A10005
(Phone Line 2) D6:D10005
(Phone Line 3) G6:G10005

The following ranges contain the phone call times in seconds (format [ss] ):
(Phone Line 1) B6:B10005
(Phone Line 2) E6:E10005
(Phone Line 3) H6:H10005

Cell B2 contains:
=COUNT(B5:B10005)

Cell B3 contains:
=IFERROR(AVERAGE(B5:B10005),"N/A")

Cells E2,E3, H2, and H3 contain corresponding formulas for their columns


Not even sure where to begin but any help would be appreciated.

Hopefully I have attached an example file that will help explain. Call times are entered at the end of each actual phone call into the corresponding column and only averages for within the same month are needed. A new spread sheet would be started for each month.

Thanks stnkynts. That's amazing. I can certainly work with that. Plus I've got a feeling I'm going to learn tons just examining the code.

I am trying to make a modification to stnkynts' solution by having the inputbox copy to the next empty cell in column M instead of just cell M1 so as to keep a running tally. But again my limited knowledge is frustrating me. Can you show me how to append column M in this manner?