Auto update /link up data with a change in cell value

HI,
I'm trying to set up a summary sheet which will bring up a client's details when i enter their name in a cell. I've attached a sample worksheet.

EG if I enter 'Post' in cell B2 in Summary worksheet, I want the data in the grey column to update with the relevant info from my Post spreadsheet.

Any idea's of how i may do this will be welcomed

Ky Van