Multiple Selection from a data validated list in the same cell

Hi,
I am trying to add a code so I can select multiple options from a drop down list so they then show in the same cell separated by comma's.
The Drop down options start in cell B1 of sheet 'list options' and continue to cell B10 of the same sheet, i would like to be able to add these options to sheet 'job sheet' in column H from cell 1 onwards.
I have also attached the spreadsheet if anyone can help it would be greatly appreciated
J