title: How to Use onOpen Trigger Script to Change Google Sheet Behavior?
body: <p>On the advice of someone below, I am editing this post:</p>
  
  <p>My initial goal is that when my Google sheet is opened, and every time it is opened, I would like the values of several Data Validation dropdown menus, currently located in Cells A10, A15, and A20, to be set to the option of "Select" -- which is a word in the validation range, along with 2 other text values.</p>
  
  <p>I have been informed that this needs to be declared at a global scope -- but I am a complete script novice and, frankly, have no idea as to how to make this work.</p>
  
  <p>Any advice will be greatly appreciated. </p>
  
  <pre><code>function onOpen() {
      SpreadsheetApp.getActiveSheet().getRange('A10').setValue('Select');
      SpreadsheetApp.getActiveSheet().getRange('A15').setValue('Select');
      SpreadsheetApp.getActiveSheet().getRange('A20').setValue('Select');
  </code></pre>