title: Create a data validation in a cell based on the value in another cell
body: <p>I have 2 columns in a spreadsheet, both are picked from a drop down list.  </p>
  
  <p>Col A is "Do you want more information" - Possible Values Yes\No</p>
  
  <p>Col B is "How did you hear about us" - Possible values are Email\Phone\Other</p>
  
  <p><strong>Question</strong>: If "No" is chosen in Col A, then Col B's value should be N/A, otherwise the user should be able to choose from the dropdown and pick a value.  Using the following formula, I can get N/A to appear, but the "false" option overwrites any available dropdown values or previously selected values.  So simply put, if Yes is chosen, let user choose a value in the other cell. If No is chosen, show N/A in the other cell.  Thoughts on how I can get this to work?</p>
  
  <p>My current formula that doesn't work (which resides in cell A2):</p>
  
  <pre><code>=IF(A1="No","N/A","Select Value")
  </code></pre>