title: Check for Numeric Value in Crystal Reports
body: <p>I need to check if a database field contains a numeric value in it.  Here is some pseudo code:</p>
  
  <pre><code>if {myField} is numeric
      // do something
  else
      // do something else
  </code></pre>
  
  <p>I'm looking for a function that will allow me to do the check '{myField} is numeric'.</p>
  
  <p>To help, here are some possible values for {myField} and what the result should be:</p>
  
  <pre><code>{myField} = ''          returns false
  {myField} = 'abc123'    returns false
  {myField} = '123abc'    returns false
  {myField} = '123'       returns true
  </code></pre>