title: Excel formula to set cell value
body: <p>I've got two columns in my Excel spreadsheet that I want to be mutually exclusive.
  e.g.
  B1 formula: IF(A1 contains "yes" then B1 set to "-") and also
  A1 formula: IF(B1 contains "yes" then A1 set to "-")</p>
  
  <p>Basically this should mean that when one cell is changed to "Yes", the other cell beside it automatically changes to"-"</p>
  
  <p>When I try to do this in the excel formula builder it says that I've created a circular formula. Does anyone know what I can do to make this work?</p>
  
  <p>Thanks</p>