title: EXTJS 4 Grid selection model row
body: <p>I have a grid and when I click on a button in the toolbar of the panel I want to check if a row in the grid is selected.
  If true I need de value of one cell of that row, so I can put it behind a url.</p>
  
  <p>But I have no idea how I can use the selection model to get the cell value of a selected row in EXT JS 4. </p>